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Foreword

This publication is a joint effort of the seven disciplines that comprise the Georgia Vegetable
Team. It is comprised of 14 topics on tomato, including history of tomato production, cultural
practices, pest management, harvesting, handling and marketing. This publication provides
information that will assist producers in improving the profitability of tomato production,
whether they are new or experienced producers.

Tomatoes are an important crop for Georgia growers; however, successful tomato production is
not easily achieved. Tomato production requires highly intensive management, production and
marketing skills, and a significant investment. Per acre cost of production is high, and yields can
be severely limited by pest problems or environment. Tomato production is complex. Expertise
in the areas of cultural practices, soils and fertility management, pest control, harvesting, post-harvest handling, marketing, and farm record keeping is crucial to profitable production.

In writing this publication, the authors have strived to provide a thorough overview of all aspects
of tomato production. However, chemical pest control recommendations are not included, as
these change from year to year. For up-to-date chemical recommendations, see the current
Georgia Pest Management Handbook.

History, Significance, Classification and Growth

William Terry Kelley and George Boyhan, Extension Horticulturists

The tomato (Lycopersicon esculentum Mill.) is the most widely grown vegetable in the United
States. Almost everyone who has a garden has at least one tomato plant. They can even be
produced in window box gardens or in single pots. Commercially, it is of equally great
importance. From processing to fresh market, and from beefsteak to grape tomatoes, the variety
and usefulness of the fruit is virtually boundless.

Tomatoes are members of the Solanaceae family, which includes peppers, eggplant, Irish
potatoes and tobacco. The tomato originated in the area extending from Ecuador to Chile in the
western coastal plain of South America. The tomato was first domesticated in Mexico where a
variety of sizes and colors were selected. The fruit was introduced to Europe in the mid-1500s.
The first ones introduced there were probably yellow since they were given the name pomodoro
in Italy, which means “golden apple.” Later the names poma armoris and pomme d’amour were
used in Italy and France. These names are both translated as “love apple.”

Tomatoes are members of the nightshade family and, because of this, were considered for many
years to be poisonous. Indeed, many crops in this family contain highly toxic alkaloids. Tomatine
occurs in toxic quantities in the tomato foliage but is converted enzymatically to a non-toxic form
in the fruit. Because of these beliefs, the crop was not used for food until the 18th century in
England and France. Tomatoes were introduced to the United States in 1710, but only became popular as a food item later in that century. Even as late as 1900, many people held the belief that
tomatoes were unsafe to eat.

Use of the crop has expanded rapidly over the past 100 years. Today more than 400,000 acres of
tomatoes are produced in the United States. The yearly production exceeds 14 million tons (12.7
million metric tons), of which more than 12 million tons are processed into various products such
as soup, catsup, sauce, salsa and prepared foods. Another 1.8 million tons are produced for the
fresh market. Global production exceeds 70 million metric tons. Tomatoes are the leading
processing vegetable crop in the United States.

California is the leading producer of processing tomatoes in the United States. Indiana, Michigan
and Ohio are other major producers. California and Florida are the leading fresh market tomato
producers in the United States. Ohio, Tennessee, Virginia and Georgia produce significant
amounts of fresh market tomatoes as well.

Tomatoes have significant nutritional value. In recent years, they have become known as an
important source of lycopene, which is a powerful antioxidant that acts as an anticarcinogen.
They also provide vitamins and minerals. One medium ripe tomato (~145 grams) can provide up
to 40 percent of the Recommended Daily Allowance of Vitamin C and 20 percent of Vitamin A.
They also contribute B vitamins, potassium, iron and calcium to the diet.

There are two types of tomatoes commonly grown. Most commercial varieties are determinate.
These “bushy” types have a defined period of flowering and fruit development. Most heirloom
garden varieties and greenhouse tomatoes are indeterminate, which means they produce flowers
and fruit throughout the life of the plant.

Tomato is considered a tender warm season crop but is actually a perennial plant, although it is
cultivated as an annual. It is sensitive to frost and will not grow perpetually outdoors in most
parts of the country. Most cultivated tomatoes require around 75 days from transplanting to first
harvest and can be harvested for several weeks before production declines. Ideal temperatures for
tomato growth are 70-85 degrees F during the day and 65-70 degrees F at night. Significantly
higher or lower temperatures can have negative effects on fruit set and quality. The tomato is a
self-pollinating plant and, outdoors, can be effectively pollinated by wind currents.

Culture and Varieties

W. Terry Kelley and George Boyhan, Extension Horticulturists

Soil Requirements and Site Preparation

Tomatoes can be produced on a variety of soil types. They grow optimally in deep, medium
textured sandy loam or loamy, fertile, well-drained soils. Avoid sites that tend to stay wet. Also,
rotate away from fields that have had solanaceous crops within the past 3-4 years. Select sites
that have good air movement (to reduce disease) and that are free from problem weeds.

In field production, plants depend on the soil for physical support and anchorage, nutrients and
water. The degree to which the soil adequately provides these three factors depends upon
topography, soil type, soil structure and soil management.

For tomato production, proper tillage is crucial for adequate soil management and optimal yields.
Land preparation should involve enough tillage operations to make the soil suitable for seedling
or transplant establishment and to provide the best soil structure for root growth and
development.

The extent to which the root systems of tomato plants develop is influenced by the soil profile.
Root growth will be restricted if there is a hard pan, compacted layer or heavy clay zone.
Tomatoes are considered to be deep rooted and, under favorable conditions, some roots will
grow to a depth of as much as 10 feet. The majority of roots, however, will be in the upper 12 to
24 inches of soil. Since root development is severely limited by compacted soil, proper land
preparation should eliminate or significantly reduce soil compaction and hard pans.

Tillage systems using the moldboard (“bottom” or “turning”) plow prepare the greatest soil
volume conducive to vigorous root growth. This allows the development of more extensive root
systems, which can more efficiently access nutrients and water in the soil. Discing after
moldboard plowing tends to re-compact the soil and should be avoided.

Compaction pans are present in many soils. They are formed principally by machinery and are
normally located at or just below plow depths. Although compaction pans may be only a few
inches thick, their inhibitory effects on root growth can significantly reduce tomato yields.

If a compaction pan exists just below or near moldboard plow depth, this hard pan can be
disrupted by subsoiling to a depth of 16 to 18 inches to allow the development of a more
extensive root system. Subsoiling also helps increase water infiltration.

If there is an abundance of plants or plant residues on the soil surface, discing or mowing
followed by discing is usually advised prior to moldboard plowing. This should be done 6 to 8
weeks ahead of planting to bury residue and allow it to decay. Immediately prior to plastic mulch
installation or transplanting, perform final soil preparation and/or bedding with a rotary tiller,
bedding disc or a double disc hiller in combination with a bedding press or leveling board. This
provides a crustless, weed-free soil for the installation of plastic mulch or the establishment of
transplants.

Tomatoes are usually transplanted into plastic mulch on raised beds. A raised bed will warm up
more quickly in the spring and therefore will enhance earlier growth. Since tomatoes do poorly in
excessively wet soils, a raised bed facilitates drainage and helps prevent waterlogging in low
areas or in poorly drained soils. Raised beds are generally 3 to 8 inches high. Keep in mind,
however, that tomatoes planted on raised beds may also require more irrigation during drought
conditions.

Cover Crops and Minimum Tillage

Winter cover crops help protect the soil from water and wind erosion. When incorporated into
the soil as “green manure,” cover crops contribute organic matter to the soil.

Soil organic matter consists of plant and animal residues in various stages of decay. Organic
matter improves soil structure (helps to reduce compaction and crusting), increases water
infiltration, decreases water and wind erosion, increases the soil’s ability to resist leaching of
many plant nutrients, and releases plant nutrients during decomposition.

The planting of cover crops and subsequent incorporation of the green manure into the soil
enhances tomato production in Coastal Plains soils. Wheat, oats, rye or ryegrass can be used as
winter cover crops. If these non-nitrogen fixing cover crops are to be incorporated as green
manure, provide them with adequate nitrogen during their growth. This increases the quantity of
organic matter produced and provides a carbon: nitrogen (C:N) ratio less likely to immobilize
nitrogen during decomposition.

As a general rule, when non-leguminous organic matter having a C:N ratio exceeding 30 to 1 is
incorporated, a supplemental nitrogen application (usually 20 to 30 pounds of nitrogen per acre)
prior to incorporation is recommended. The exact rate required will depend on the C:N ratio,
soil type and amount of any residual nitrogen in the soil. Plow green manure crops under as
deeply as possible with a moldboard plow 4 to 6 weeks prior to installing mulch or transplanting
tomatoes.

Planting tomatoes in reduced tillage situations has been tried with variable results in different
parts of the country. Often cover crops can be killed with a burn down herbicide. Then tomatoes
are either transplanted directly into the cover, or a narrow strip is tilled and prepared for
transplanting while leaving the residue between rows. While these residues can protect the fruit
from direct contact with the soil, currently the impediments outweigh the benefits for large-scale
commercial production. Leguminous covers can provide nitrogen to the crop and there are
certainly soil conservation advantages.

The primary encumbrance to success in reduced tillage systems is adequate weed and disease
control. The application of phosphates, potash and lime are also more difficult in these systems,
so reduced tillage is used only on a limited basis in commercial tomato production. With
advances in weed and disease control technology, this type of production may become more
feasible in the future.

Windbreaks

Crop windbreaks can aid in crop protection and enhance early growth and yield. Frequency or
intervals between windbreaks is dictated by distance between tomato rows, spray or harvest
alleyway intervals, land availability and equipment characteristics. For instance, bed
arrangements may be such that a windbreak is present between every set of four, six or eight
beds. Plant windbreaks perpendicular to the prevailing wind direction. When using a taller
growing windbreak such as rye, you can expect the windbreak to be effective to a width of about
10 times its height. For instance, with a rye crop that is 3 feet high, the windbreaks can be
effective up to 30 feet apart.

In general, close windbreaks give the best wind protection and help moderate the tomato plants’
microenvironment and enhance earliness. Especially on sandy soils, windbreaks reduce damage
from sandblasting of plants and small fruit during early spring. Sandblasting can be more of a
problem with plastic mulch, as the soil particles are carried easily by the wind across the field.
Many growers spread small grain seed after the plastic mulch is applied to reduce sand blasting.
Windbreaks also conserve soil moisture by reducing direct evaporation from the soil and transpiration from the plant. This can enhance plant growth throughout the season.

Regardless of the species selected to be used as a windbreak, plant it early enough to be effective
as a windbreak by the time tomatoes are transplanted. Establishment of a windbreak crop during
the fall or early winter should ensure enough growth for an effective windbreak by spring tomato
planting time. Wheat, oats or rye all make good windbreak crops. Windbreaks can be living or
non-living. Tomato beds can be established between the windbreaks by tilling only in the bed
area.

To minimize insect migration to the tomato crop, destroy windbreak crops by herbicides,
mowing and/or tillage before they lose their green color and begin to die back.

Transplanting

Seeding tomatoes directly into the field is not recommended due to the high cost of hybrid seed
and the specific conditions required for adequate germination. Most tomatoes are transplanted to
the field from greenhouse-grown plants. Direct seeding has other disadvantages: (1) Weed
control is usually much more difficult with direct seeded than with transplanted tomatoes; (2)
direct seeding requires especially well made seedbeds and specialized planting equipment to
adequately control depth of planting and in-row spacing; (3) because of the shallow planting
depth required for tomato seed, the field must be nearly level to prevent seeds from being washed
away or covered too deeply with water-transported soil; and (4) spring harvest dates will be at
least 2 to 3 weeks later for direct seeded tomatoes.

Typically, 5- to 6-week old tomato seedlings are transplanted into the field. As with most similar
vegetable crops, container-grown transplants are preferred over bare root plants. Container grown
transplants retain transplant growing medium (soil-substitute) attached to their roots after
removal from the container (flat, tray). Many growers prefer this type transplant because (1) they
are less subject to transplant shock, (2) usually require little, if any, replanting, (3) resume growth
more quickly after transplanting, and (4) grow and produce more uniformly. Tomato plants
produced in a 1-inch cell size tray are commonly used for transplanting. Many growers will use a
1.5-inch cell tray for transplant production in the fall when transplant stress is greater.

Tomato transplants should be hardened off before transplanting to the field. Hardening off is a
technique used to slow plant growth prior to field setting so the plant can more successfully
transition to the less favorable conditions in the field. This process involves decreasing water for
a short period prior to taking the plants to the field. Research shows that reducing temperatures
too drastically to harden tomato transplants can induce catfacing in the fruit.

For maximum production, transplants should never have fruits, flowers or flower buds before
transplanting. An ideal transplant is young (6 inches to 8 inches tall with a stem approximately ¼
inch to ⅜ inch in diameter), does not exhibit rapid vegetative growth, and is slightly hardened at
transplanting time. Rapid growth following transplanting helps assure a well established plant
before fruit development. In most cases, it is more economically feasible to have transplants
produced by a commercial transplant grower than to grow them on the farm. When purchasing
transplants, be sure the plants have the variety name, have been inspected and approved by a
plant inspector, and they are of the size and quality specified in the order.

Set transplants as soon as possible after removing from containers or after pulling. If it is
necessary to hold tomato plants for several days before transplanting them, keep them cool
(around 55-65 degrees F if possible) and do not allow the roots to dry out prior to transplanting.
When setting plants, place them upright and place the roots 3 to 4 inches deep. Setting plants at
least as deep as the cotyledons has been shown to enhance plant growth and early fruit
production and maturity. Completely cover the root ball with soil to prevent wicking moisture
from the soil. Tomatoes grow best if nighttime soil temperatures average higher than 60 degrees
F.

At transplanting, apply an appropriate fertilizer starter solution (see Fertilizer Management section). After transplanting (especially within the first 2 weeks) it is very important that soil
moisture be maintained so that plant roots can become well established.

Plant Spacing

Tomatoes can be planted in one of many different arrangements that provide adequate space for
plant growth. Often the spacing is based on the type of trellising and equipment that will be used
in the field. The within-row and between-row spacings are selected to meet these limitations. The
optimal plant population per acre may also be influenced by plant growth habit (compact,
spreading), plant size at maturity (small, medium, large), vigor of specific cultivars, climate, soil
moisture, nutrient availability, management system and soil productivity.

Generally, for production of determinate varieties on plastic mulch, a minimum of 5 feet between
rows is used with an in-row spacing of 18 to 24 inches. Six feet between rows is also a popular
interval. To space plants 22 inches apart in rows that are 5 feet apart requires 4,760 plants per
acre. With 6-foot centers and 18 inches between plants, 4,840 plants are required per acre.
Usually a single row of tomatoes is planted down the center of each plastic mulched bed.

On bare ground, space rows 48 to 72 inches apart with 18 inches to 24 inches between plants in
the row. For indeterminate types of tomatoes, which produce larger plants, adjust spacing to
decrease the population accordingly.

Varieties

Select varieties on the basis of marketable yield potential, quality, market acceptability,
adaptability and disease resistance or tolerance. The selection of a variety(ies) should be made
with input from the buyer of the crop several months in advance of planting. Other characteristics
to consider include maturity, size, shape, color, firmness, shipping quality and plant habit.

There are a plethora of commercially available tomato varieties, many of which will perform well
under Georgia conditions. Varieties will perform differently under various environmental
conditions. Yield, though ultimately important, should not be the only selection criteria.
Tomatoes produced on plastic mulch with drip irrigation will commonly average more than
1,500 25-pound cartons per acre. Select varieties that have yield potential that equals or surpasses
this average.

Plants also need to produce adequate foliage to protect fruit. Basically, a variety must be
adaptable to the area, produce a competitive yield and be acceptable to buyers. Disease resistance
will be most important with diseases for which there are no other good management options.
Varieties produced in Georgia should be resistant to Fusarium wilt (Races 1 and 2) and
Verticillium wilt (Race 1). In recent years, resistance to Tomato Spotted Wilt Virus has become
equally as important, since varietal resistance is the most effective control method at this time.
Other resistance of significance should include Gray Leaf Spot and Tobacco Mosaic Virus.

All commercially important tomatoes grown in Georgia belong to the species Lycopersicon
esculentum. Table 1 lists those varieties that have performed well in Georgia or in similar areas
of the southeastern United States. Notations in the disease resistance column indicate either
resistance or tolerance. Some varieties may not exhibit complete resistance to the disease listed.

Table 1. Tomato varieties that have exhibited acceptable performance either in variety trials or in grower fields in Georgia.

Staking and Pruning

Most commercial determinate tomatoes are produced using short stake culture for trellising. This
type of culture produces fruits that are higher in quality and easier to harvest and enhances spray
coverage. In this system, stakes approximately 4 feet long and ¾ to 1 inch square are placed
between every one or two plants depending on the tying system that is employed. Stakes are
usually driven about 12 inches into the ground. An additional stake can be supplied at the ends of
each section to strengthen the trellis.

Stake plants immediately after planting to minimize damage to the root system and to have the
trellis ready when needed. Plants are usually tied initially when they are about 12-15 inches tall
and should be tied prior to any plants lodging. The first string is usually placed about 10 inches
above the ground. Subsequent tyings are placed about 6 inches above the previous one.
Determinate varieties may be tied as many as three to four times.

The Florida weave system is one method of tying that is often used. In this system, a stake is
placed between every other plant in the row. Twine is then used to tie the plants using a figure
eight weave. The twine is wrapped around the stake and is pulled tightly on one side of the first
plant and then between the two plants and along the other side of the second plant. At the end of
the row or section, the pattern is reversed and, as the twine is wrapped around each stake, the
twine is then placed on the other side of each plant going back in the opposite direction along the
row. This system uses fewer stakes and encloses the plant with the twine. Subsequent tyings
often do not weave between plants but simply go along one side of the plants going one way and
the opposite side going the other direction.

Another system of tying involves placing a stake after every plant. The twine is then simply
wrapped around each stake and along one side of the plant going along the row and around the
other side of the plant coming back in the other direction on the opposite side of the row.
Regardless of the system used, the twine should be held with enough tension to adequately support the plants. If the twine is too tight, however, it can impede harvest and damage plants and fruit.

Tomato twine should be resistant to weathering and stretching and should not cut into the plants
or fruit. It takes about 30 pounds of synthetic twine per acre for tomatoes. A simple tying tool can
be made from conduit or PVC pipe that is 2 to 3 feet long. The twine is passed through the pipe
to act as an extension of the worker’s arm. This limits the need to stoop over at each stake to
wrap the twine. A similar tool can be made from a wooden dowel or narrow wooden strip. With
these, a hole is drilled about 1 inch from each end of the piece of wood and the string passed
through each hole. This provides the same extension of the hand as the other method.

Determinate tomatoes often still require some level of pruning. Pruning is the removal of suckers
(axillary shoots). The degree to which pruning is needed will vary with the variety used but can
impact yield and quality significantly. Plants that produce vigorous foliage that are not pruned
will produce more, but smaller fruit. Pruning helps increase the size of the fruit. It can also
enhance earliness of the crown set, reduce pest pressure and enhance spray coverage. In general,
pruning will involve removal of one to all suckers up to the first fork (the sucker just below the
first flower cluster).

Growers should experiment with individual varieties to determine the degree of pruning needed.
Often the seed supplier can provide information on specific varieties regarding pruning. Some
varieties require only the removal of ground suckers (at the cotyledons) or none at all.
Overpruning can cause reduced yields and increased sunburn, blossom end rot and catfacing.
More vigorous varieties may require the removal of ground suckers plus two additional suckers.
Remove suckers when they are small (2 to 4 inches long). Removal of large suckers is more
time consuming and can damage the plant. Prune before the first stringing to facilitate the
process, since the strings may be in the way. A second pruning may be required to remove
suckers that were not large enough to remove easily during the first pruning and to remove
ground suckers that may have developed. Prune plants when the foliage is dry to reduce the
spread of disease.

Transplant Production

George E. Boyhan and W. Terry Kelley, Extension Horticulturists

Tomato production in Georgia is an expensive, labor intensive endeavor developed to produce
high quality fresh market fruit. Because of the cost involved and because early market fruit
command higher prices, growers exclusively use transplants to produce tomatoes. Tomato
transplant production is a relatively easy but highly specialized function of production. Many
growers have neither the greenhouse facilities nor the expertise to undertake transplant
production; instead, they will rely on greenhouse growers to produce their transplants. For these
growers to ensure a quality supply of transplants, they should contract early with their greenhouse
grower to secure plants of the variet(ies) they wish to grow.

Growers should expect to plant between 3,600 and 5,800 plants per acre in a staked tomato
operation, depending on the plant spacing. Expect to produce about 4,000 transplants per ounce
of seed with approximately 3 ounces required to produce 10,000 seedlings. For example, to
produce 10 acres of tomatoes with 5,800 plants per acre would require 58,000 transplants and
would require about 18 ounces of seed (rounding up to 60,000 plants). Many seed companies no
longer sell seed by weight but by count and will supply the germination rate as well. In such a
case, the count and germination rate can be used to estimate the amount of seed to plant to
produce the desired number of plants. For example, to produce 58,000 seedlings from seed with
90 percent germination would require 64,445 seed (58,000 divided by 0.90).

Tomato seedlings are usually produced in trays or flats that are divided into cells. Tomatoes
require a cell size of approximately 1 inch square to produce a high quality, easily handled
transplant. These trays or flats are available in a number of different configurations and sizes.
They may be purchased as flats and inserts, polystyrene trays or, more recently, as one-piece rigid
polyethylene plastic trays. Growers should make sure the trays or flats used can be handled with
their transplanting equipment.

Media for production is usually peat based with various additives such as perlite and vermiculite
to improve its characteristics. These can be purchased ready mixed or you can formulate your
own mix. The individual components of peat moss, perlite, vermiculite, etc., can be purchased.
Whether buying the individual components or a ready-made product, it is advisable to use finer
textured media when starting seed. Check with your supplier about media texture. Some media
are specially made for this purpose. In addition, these media may have fertilizer and wetting
agents mixed in. Media with fertilizer is often referred to as charged.

Treated and/or coated seed may be used to produce seedlings. Most seed is sold with a fungicide
applied to the seed. This will help prevent damping off during the germination process. In
addition, various seed coats are available, from polymer to clay coats. These are useful when
using automated seeding equipment to aid in seed singulation. Plant tomato seed ⅛ to ¼ inch
deep. With an automated seeder, the seed will be placed on the surface and will have to be
covered, usually with a thin layer of vermiculite.

After flats have been filled and the seed planted, they are often wrapped with plastic pallet wrap
or placed in germination rooms (rooms with temperature and humidity tightly controlled) for 48-72 hours to ensure even moisture and temperature for optimum germination. The optimum
germination temperature for tomatoes is 85 degrees F, at which tomato seedlings should emerge
in about 5-6 days. See Table 2 for soil temperatures and number of days to germination.

Table 2. Soil temperature and days to germination.

Soil Temperature (ºF)

60

68

77

85

95

Days to Emergence

14

8

6

5

9

If charged media is used, there will be no need for fertilizer for the first 3 to 4 weeks of
production. After that, use 150-200 ppm of a suitable water soluble fertilizer once per week
(Table 3). With media that has no premixed fertilizer, begin fertilization as soon as the plants
emerge. Growers may wish to use as little as 50 ppm of a suitable water soluble fertilizer with
every irrigation. Tomatoes will require approximately 5 to 7 weeks to produce a good quality
transplant. Cooler temperatures will slow growth, so greenhouse temperatures should be kept
above 60 degrees F at night to accelerate growth.

Prior to transplanting, tomatoes should be hardened off. This is the process of reducing water
and/or lowering temperature. Do this several days prior to transplanting. A good way to achieve
this is to move the plants outside the greenhouse to a protected location (some shade), or open
the sides of the greenhouse if possible. Reduce the amount of water the plants receive, but don’t
allow the plants to wilt. Hardening plants is critically important to ensure survivability.
Unhardened plants are much more vulnerable to environmental extremes.

A good quality transplant will be a sturdy, compact plant with a root mass that completely fills
the cell. Water plants prior to transplanting. Tomatoes can be transplanted deeper than
they grew in the greenhouse container and, in fact, it is desirable to do so. Roots will form on the
stem that is below the ground.

Take care when transplanting into black plastic so the plants do not touch the plastic. The plastic
can absorb enough heat to injure and kill plants. A drench of about 0.5 pint of a suitable
starter solution should be applied to each plant. Examples of suitable solutions include mixing 3
pounds of 11-34-0 or 18-46-0 fertilizer in 50 gallons of water. Most transplanting equipment will
have a tank to hold the solution and will automatically dispense the solution to each plant.

Carefully monitor plants for the first few days to a week after transplanting to ensure survival.
Note any problems with dry soil, clogged irrigation, plants touching the plastic, etc., and take
corrective action.

Production Using Plastic Mulch

W. Terry Kelley, Extension Horticulturist

The use of plastic mulch in the commercial production of staked tomatoes is almost universal in
the south-east. Plastic mulch is used to promote earliness, reduce weed pressure, and to conserve
moisture and fertilizer. Most often drip irrigation is used in conjunction with plastic mulch.
There are both advantages and disadvantages to producing crops under this system.

Furthermore, where fumigants are used, plastic mulch provides a barrier that increases fumigant
efficiency. Plastic mulch also keeps fruit cleaner by reducing soil spatter. When using drip
irrigation particularly, disease is often reduced as the foliage stays drier and, again, soil is not
splashed onto the plant.

Disadvantages: Specialized equipment is required to lay plastic mulch, which means increased
variable costs for custom application or the purchase of this equipment. Yellow and purple
nutsedges are not controlled by black plastic mulch, and suitable fumigants/ herbicides must be
applied if nutsedge is a potential problem. The cost of plastic removal and disposal is an
additional expense.

In most instances, plastic mulch culture has increased yields and returns sufficiently to offset
these potential disadvantages.

Types of Plastic

One to 1.25 mil black plastic is the cheapest and traditionally has been most often used in spring
tomato production. Embossed plastic has a crimped pattern in the plastic that allows the mulch to
stretch and contract so it can be laid snug to the bed. This can be important, particularly in
multiple cropping operations where, for example, spring tomatoes may be followed by fall
cucumbers. The embossed plastic is less likely to be damaged by wind and other environmental
factors, thus increasing the potential for use on multiple crops.

Summer planted tomato crops for fall production cannot tolerate excessively high soil
temperatures. They should be planted on white plastic, which reflects some surface heat and does
not warm the soil as much. For spring production, however, white is not recommended since
maximum soil warming is needed. In lieu of using white plastic, many growers use a dilute white
paint sprayed over the bed to lighten the plastic and reflect heat for fall production.

Recently, metalized mulches have become popular. These plastic mulches have a thin film of
metal that is applied with a vacuum which produces a reflective effect. Research has shown that
these mulches can help reduce the incidence of Tomato Spotted Wilt Virus infection on tomatoes
by repelling thrips. However, these mulches do not warm the soil as well as black mulches,
resulting in reduced plant growth early in the spring. Often, these plastics are produced with a
black strip down the middle with the shoulders metalized. This allows for heat retention to get
the earliness effect while producing the reflective effect needed to repel thrips and reduce
TSWV. Recent research has also shown that metalized mulches also retain fumigants better and
may allow for use of reduced rates.

Virtually Impermeable Films (VIF) are used in some parts of the world to reduce fumigant
release into the atmosphere. These films are as yet not routinely available in the United States,
are more expensive and, depending on the fumigant, can increase the preplant interval.

Although biodegradable plastic mulches are presently available, they have not been proven to be
beneficial. Since most growers want to get two, three or four crops using the same plastic,
biodegradable plastics break down too quickly to allow this. When perfected, these materials
have the potential to greatly reduce the cost of plastic removal and disposal. Growers using a
biodegradable plastic mulch for the first time should test it on a small area until its effectiveness
under their conditions is proven.

Bed Preparation

Bed height and width depend on several factors including soil type, bedding equipment, available
plastic, etc. Standard bed heights range from 4 to 8 inches. Bed width is also dictated by
equipment and grower preference. Current top widths of beds range from 28 to 36 inches.
Ordinarily plastic mulch must be 20 to 24 inches wider than the bed width preferred, so it will
cover the sides of the bed and can be tucked under the soil to anchor the plastic. The plastic must
fit firmly over the bed to minimize wind movement and facilitate planting. Mulch must be
covered at the ends of each bed to prevent wind from getting under the plastic and fumigant from
escaping. Any available opening, such as a tear or uncovered tuck, that allows wind entry will
cause problems.

Use trickle or drip irrigation with plastic mulch for maximum efficiency. It is still important,
however, to have optimum soil moisture during plastic application. The use of overhead
irrigation requires punching additional holes in the plastic to facilitate water entry, which
compromises the integrity of the plastic and reduces its effectiveness in controlling weeds and
minimizing leaching of nutrients.

Land preparation for laying plastic is similar to that described in the prior chapter on culture and
varieties. The site should still be deep turned and rototilled. Usually a hipper is used to form a
high ridge of soil down the middle of the bed to assure the bed pan is filled with soil. This creates
a firm, full bed. The bed pan should leave a bed with a slight crown in the middle that slopes
slightly to each side. This prevents water from standing on the plastic or being funneled into the
holes and waterlogging the soil. Generally, fumigant is applied as the bed pan passes and plastic
is installed just behind the pan. Drip tape is installed at the same time, just in front of the plastic,
and should be buried 1 inch below the surface to prevent “snaking” under the plastic and to
reduce rodent damage to the tape. Drip tape buried deeper will be difficult to remove and will not
wet the upper portion of the root zone. Soil moisture should be good at the time plastic is
installed to ensure a good, firm bed.

Fertilizer Management Under Plastic

Apply any needed lime 2 to 3 months ahead of plastic mulch installation. Preplant fertilizer
application will vary with bed size and planting scheme. On larger beds (4 feet wide or greater),
it is advisable to incorporate all phosphorus and micronutrients into the bed before installing
plastic. If drip fertigation is not used, apply all the nitrogen and potassium preplant as well.

If narrower beds are used, preplant application of all the needed fertilizer may cause fertilizer salt
toxicity. Sidedressing is required, therefore, by a liquid injection wheel, through drip irrigation,
or a banded application outside the tucked portion of the bed.

Most tomatoes are planted where fertigation with drip irrigation is used. In these cases all the
phosphorous (P) and micronutrients, and one-third to one-half of the nitrogen (N) and potassium
(K) should be incorporated into the bed before the plastic is laid. Apply the remaining N and K
through weekly fertigations beginning just after transplant establishment. The rate of application
of these fertigations will change with the stage of the crop.

Planting into Plastic Mulch

Tomatoes are transplanted with a tractor mounted implement that uses a water wheel to punch
holes in the plastic at the appropriate interval. A person (or persons) riding on seat(s) mounted
behind the water wheel(s) places a transplant into the newly formed hole and covers the rootball.
An alternate approach used by many producers is use of a water wheel or similar device to punch
holes, with a crew of people walking the field and hand setting plants. The plants are then
watered with a water wagon following the setting crews.

If a fumigant is used for soil sterilization, it will be necessary to wait the prescribed time period
before punching holes into the plastic to ensure good fumigant activity and avoid phytotoxicity.
If an appropriate waiting period is not observed, some soil fumigants can destroy tomato
transplant roots and cause stunting or plant death.

Other types of transplant methods are available as well. Carousel type planters are sometimes
used, which will punch a hole in the plastic and set the plant all in one operation. This equipment
requires fewer people to operate since only one person is needed per row. These implements are
often slower and usually someone has to walk behind the planter to make sure plants are covered
well.

Irrigation

Kerry Harrison, Extension Engineer

Irrigation is essential to produce consistent yields of high quality tomatoes in Georgia. Rainfall
amounts are often erratic during the growing season, and tomatoes are often grown in sandy soils
with low water holding capacity. This combination of factors makes supplemental irrigation
necessary for commercial tomato production.

Irrigation studies in the southeast show that irrigation increases annual tomato yields by an
average of at least 60 percent over dryland production. Quality of irrigated tomatoes is also much
better. Irrigation eliminates disastrous crop losses resulting from severe drought.

Tomatoes are potentially deep rooted, with significant root densities up to 4 feet deep. In Georgia
soils, however, the effective rooting depth is generally much less. Actual root depths vary
considerably depending upon soil conditions and cultural practices. The effective rooting depth is
usually 12 to 18 inches with half of the roots in the top 6 inches. It is important not to allow
these roots to dry out or root damage will occur.

Moisture stress in tomatoes causes shedding of flowers and young fruit, sunscalding and dry rot
of fruit. The most critical stages for watering are at transplanting, flowering and fruit
development.

Several types of irrigation may be used successfully on tomatoes in the southeast. Ultimately, the
type chosen will depend on one or more of the following factors:

Availability of existing equipment

Field shape and size

Amount and quality of water available

Labor requirements

Fuel requirements

Cost

Sprinkler Irrigation

These systems include center pivot, linear move, traveling gun, permanent set and portable
aluminum pipe with sprinklers. Any of these systems are satisfactory if they are used correctly.
There are, however, significant differences in initial cost, fuel cost and labor requirements.

Any sprinkler system used on tomatoes should be able to deliver at least an inch of water every 4
days. In addition, the system should apply the water slowly enough to prevent run-off. In sandy
soils, the application rate should be less than 3 inches per hour. In loamy or clay soils, the rate
should not exceed 1 inch per hour.

Sprinkler systems with a high application uniformity (center pivot, linear move and permanent
set) can be used to apply fertilizer. This increases the efficiency of fertilizer utilization by making
it readily available to the plant and reduces leaching.

Drip Irrigation

Drip irrigation has become the standard practice for tomato production. Although it can be used
with or without plastic mulch, its use is highly recommended with plastic mulch culture. One of
the major advantages of drip irrigation is its water use efficiency. Studies in Florida indicate that
drip irrigated vegetables require 40 percent less water than sprinkler irrigated vegetables. Weeds
are also less of a problem, since only the rows are watered and the middles remain dry. Some
studies have also shown significant yield increases with drip irrigation and plastic mulch when
compared with sprinkler irrigated tomatoes. The most dramatic yields have been attained by
using drip irrigation and plastic mulch, and supplementing nutrients by injecting fertilizers into
the drip system (fertigation).

Drip tubing may be installed on the soil surface or buried up to about 1.5 inches deep. When used
in conjunction with plastic mulch, the tubing can be installed at the same time the plastic mulch
is laid. Usually one line of tubing is installed on each bed. A field with beds spaced 5 feet center
to center will require 8,712 feet of tubing per acre (one tube per bed). The output rate of the tube
is specified by the user. For discussion purposes, however, you can determine the per acre water
capacity by multiplying the output rate of the tube (per 1000') by 8.712 (i.e., on a 5' bed spacing a
4.5 gpm/1000' output rate tube will require 39.2 gpm per acre water capacity).

The tubing is available in various wall thicknesses ranging from 3 mils to 25 mils. Most growers
use thin wall tubing (10 mils or less) and replace it every year. Heavier wall tubing can be rolled
up at the end of the season and reused; however, take care in removing it from the field and store
it in a shelter. Labor costs for removing, storing and reinstalling irrigation tubing are often
prohibitive.

Excellent results have been achieved by injecting at least half of the fertilizer through the drip
system. This allows plant nutrients to be supplied to the field as needed. This method also
eliminates the need for heavy fertilizer applications early in the season, which tend to leach
beyond the reach of root systems or cause salt toxicity problems. Only water soluble formulations
can be injected through the drip systems. Nitrogen and potassium formulations tend to be more
water soluble than phosphorous and, consequently, are more easily injected. These nutrients also
tend to leach quicker and need to be supplemented during the growing season. Thoroughly flush
drip systems following each fertilizer injection.

Water used in a drip irrigation system should be well filtered to remove any particulate matter
that might plug the tubing. Test the water for minerals that could precipitate and cause plugging
problems.

Scheduling Irrigation

The combined loss of water by evaporation from the soil and transpiration from plant surfaces is
called evapotranspiration (ET). Peak ET rates for tomatoes are about 0.2 inch per day. Factors
affecting ET are stage of crop growth, temperature, relative humidity, solar radiation, wind velocity and plant
spacing. Transplant tomatoes into moist soil and irrigate with 0.3 to 0.5 inch immediately after
transplanting to settle the soil around the roots.

Once a root system is established, maintain soil moisture to the 12-inch depth. The sandier soils
in south Georgia have an available water holding capacity of about 1 inch per foot of soil depth.
You should not deplete more than 50 percent of the available water before irrigating; therefore,
when you use 0.5 inch, it should be replaced by irrigation. Soils having a higher clay content may
have water holding capacities as high as 2 inches per foot. In these soils you can deplete as much
as 1 inch before irrigating. This means net application amounts should be between 0.5 and 1.0
inch per irrigation. The actual amount applied should be 10 to 20 percent higher to account for
evaporation losses and wind drift. The irrigation frequency will depend on daily
evapotranspiration. In general, for sprinkler irrigated tomatoes during peak water use periods,
sandy soils should receive 0.6 inch two or three times a week, and clay soils should receive 1.25
inches about every 5 days.

Irrigation can best be managed by monitoring the amount of moisture in the soil. This can be
done with soil moisture blocks. For best results on tomatoes, maintain soil moisture below 30
centibars. Drip irrigation systems need to be operated more frequently than sprinkler systems.
Typically, they are operated every day or every other day. Do not saturate the soil with water,
especially when using plastic mulch. Plastic mulch will tend to keep the soil from drying out and
tomatoes grow poorly in waterlogged soil.

Physiological Problems

George Boyhan and W. Terry Kelley, Extension Horticulturists

Several physiological problems can affect tomatoes. Most of these are due to specific adverse
environmental conditions. Growers can do some things to help minimize their impact, but in
many cases not much can be done. In addition, many of these conditions are not well understood,
so corrective action is not always possible.

Blossom-End Rot

Blossom-end rot is a calcium deficiency that occurs at the blossom end of the fruit. It is
characterized by black, necrotic, sunken tissue at the blossom end. Fruit with necrotic tissue is
unsalable and the damage cannot be corrected. Although the tissue is calcium deficient, preplant
applications of calcium or postplant applications to correct the disorder often have no effect.

Blossom-end rot develops very early in fruit formation when fruit is smaller than a fingernail,
which is a critical time for calcium deposition in newly forming tissue. Calcium is relatively
immobile in plants. Once it becomes part of the plant tissue in one location, it cannot be easily
moved to new developing tissue. Further, calcium moves in the water stream of the plant’s
vascular tissue. So during hot ,dry conditions with high transpiration, calcium uptake may be
high but may not be moving laterally into forming fruit. This results in deficiency in these
developing tissues even though there is sufficient calcium present in the soil and available to the
plant. There is evidence indicating that unstaked and unpruned plants are less likely to have this
problem, but in Georgia most tomatoes are staked and pruned for ease of harvest and quality of
fresh market fruit.

To a certain extent, this problem can be alleviated with even moisture during plant growth. Wide
swings from wet to dry conditions as well as overwatering tend to aggravate this problem.
Exogenous applications of calcium as foliar sprays have been suggested to alleviate this problem.
Any such application would have to occur prior to visible symptoms when fruit are just forming,
but there is little evidence this is an effective practice.

Blossom Drop

Although tomatoes are warm season vegetables, they require relatively moderate temperatures to
set fruit. Nighttime temperatures above 70 degrees F. will cause blossom drop, which in turn will
reduce yields.

This problem is solved by planting at that time of year when night temperatures will be below
this threshold during flowering and fruiting. Transplanting dates for south Georgia would be
from March 1 to April 30 in the spring and from July 15 to August 15 in the fall. In north
Georgia this would be from April 15 to June 15 in the spring and it is not recommended that
tomatoes be grown in the fall. In addition to planting date, there are “hot set” tomatoes available.
These tomatoes have been bred to set fruit under higher temperatures (see Table 1 for varieties).
For fall planted tomatoes, hot set types are recommended.

Fruit Cracking

Tomato fruit are prone to cracking under certain circumstances. There are two different types of
cracking — radial and concentric — both of which occur at the stem end. Radial cracking is
more common and usually occurs during periods of high temperatures (at or above 90 degrees F.)
and prolonged rain or wet soil when fruit will rapidly expand and often crack. This is particularly
prevalent after a long period of dry weather. This type of cracking is also more prone to occur if
fruit are exposed to intense sunlight. Finally, fruit load may also be a factor, with a light load
more prone to cracking.

Maintaining even moisture conditions, avoiding excessive pruning, and having a heavy fruit load
will help prevent this problem. Variety selection can also help alleviate this problem. Varieties
are available that are resistant to cracking. Generally, cracking susceptible varieties will crack
when fruit are still in the green stage, whereas resistant varieties often don’t show cracking until
later, when the fruit is turning color.

Concentric cracking is also caused by rapid growth, but generally occurs when there are
alternating periods of rapid growth followed by slower growth. This can occur with wet/dry
cycles or cycles of high and low temperatures. Generally this type of cracking occurs as fruit near
maturation. Even moisture throughout the growing period will help alleviate this problem. Also
avoid fertilization spikes that encourage cyclic growth.

Catfacing

Catfacing is characterized by distorted growth at the blossom end of fruit, often with rough
calloused ridges. Catfacing generally occurs when fruit are formed during cool or humid weather
that favors the corolla adhering to the developing fruit. The adhesion of these flower parts causes
the distortion that appears as the fruit matures. Usually catfacing is most evident during the first
harvest with fruit that was set during cooler temperatures. Planting later and using varieties
resistant to catfacing will help prevent this from occurring.

Zippering may be related to catfacing, only the damage occurs in straight lines from the blossom
end to the stem end. The line may have a calloused or corky appearance.

Puffiness

Fruit may appear normal or nearly so but, when cut, the locules appear empty. There is little or
no fruit gel or seeds present. This usually occurs when fruit develop under conditions that are too
cool or too hot (below 55 degrees F or above 90 degrees F.), which interferes with normal seed
set. Tomatoes are self-fertile but require some disturbance of the flower in order for the pollen to
be shaken onto the stigma. This can occur from insects or wind, or during the normal handling of
plants (staking and pruning). Wet, humid and cloudy weather may interfere with insect
pollination and the pollen may not shed as readily. Cool weather will slow the growth of pollen
tubes. In addition, excess nitrogen appears to be a factor with this condition.

Little can be done to alleviate this problem other than planting at the proper time of year. Hot set
varieties appear to be less susceptible to this problem.

Sunscald

Tomato fruit may develop a papery thin area on the fruit that will appear tan or white in color.
This is caused by sunscald, where the area affected is exposed to intense sunlight and heat
resulting in a breakdown of the tissue. Sunscald may also appear as hard yellow areas on the fruit
that are exposed. Maintaining good foliage cover during fruit development and avoiding
excessive pruning will minimize this problem.

Graywall or Blotchy Ripening and Internal Browning

Several different factors may contribute to these conditions. Internal browning may be caused by
a virus (tobacco mosaic virus; see the disease section). Silverleaf whitefly has also been
associated with uneven ripeness in tomatoes (see section on insects).

Graywall and blotchy ripening may occur together and may be caused by a bacteria. The outer
wall will appear gray and be partially collapsed. Internally there are necrotic areas within the
walls of the fruit. Factors associated with this condition include high nitrogen, low potassium,
low temperatures, excessive soil moisture and soil compaction. Addressing these factors may
reduce the incidence of this disorder.

Internal White Tissue

Occasionally, a tomato will exhibit white tissue in the crosswalls when cut. This is rarely seen
when fruit are harvested at the mature green stage, but it can be a problem with vine ripe fruit. It
is unclear what causes this, but adequate potassium fertilizer appears to reduce the problem.

Rain Check

Rain check is the formation of tiny transverse cracks on the fruit. These cracks may heal, forming
a rough texture on the fruit; generally these fruit are unmarketable.

As with many of these disorders, it is unclear what causes this, but it is associated with rain
events. Heavy rains following dry periods are times when this is most likely to occur. This
phenomenon may be related to other types of cracking and may be alleviated with growing
conditions that don’t encourage wet/dry cycles.

Lime and Fertilizer Management

W. Terry Kelley and George E. Boyhan, Extension Horticulturists

Lime and fertilizer management should be tailored to apply optimal amounts of lime and
nutrients at the most appropriate time(s) and by the most effective application method(s).
Fertilizer management is impacted by cultural methods, tillage practices and cropping sequences.
A proper nutrient management program takes into account native soil fertility and residual
fertilizer. Therefore, the first step in an appropriate fertilizer management program is to properly
take a soil test 3 to 5 months before the crop is to be planted.

Soil pH

Adjusting the soil to the appropriate pH range is the first consideration for any fertilizer
management program. The soil pH strongly influences plant growth, the availability of nutrients,
and the activities of microorganisms in the soil. It is important to keep soil pH in the proper
range in order to produce the best yields of high quality tomatoes. Soil tests results indicate soil
pH levels and also provide recommendations for any needed amounts of lime required to raise
the pH to the desired range.

The optimum pH range for tomato production is 6.2 to 6.8. Most Georgia soils will become
strongly acid (pH 5.0 or less) with time if lime is not applied. Continuous cropping and
application of high rates of nitrogen reduce pH at an even faster rate. Lime also adds calcium
and, with dolomitic lime, magnesium to the soil.

Calcium has limited mobility in soil, so broadcast and thoroughly incorporate lime to a depth of 6
to 8 inches. This will also neutralize soil acidity in the root zone. To allow adequate time for
neutralization of soil acidity (raising the pH), lime should be applied and thoroughly incorporated
2 to 3 months before seeding or transplanting. However, if application cannot be made this early,
liming will still be very beneficial if applied and incorporated at least 1 month prior to seeding or
transplanting.

The two most common liming materials available in Georgia are calcitic and dolomitic
limestone. Dolomitic limestone also contains 6 to 12 percent magnesium in addition to calcium.
Since many soils, and particularly lighter Coastal Plains soils, routinely become deficient in
magnesium, dolomitic limestone is usually the preferred liming material.

Fertilizer Management and Application

Recommending a specific fertilizer management program universal for all tomato fields would
result in applications that are inefficient and not cost effective. In addition to crop nutrient
requirements and soil types, fertilizer recommendations should take into consideration soil pH,
residual nutrients and inherent soil fertility. Therefore, fertilizer recommendations based on soil
test analyses have the greatest potential for providing tomatoes with adequate but not excessive
fertility. Applications limited to required amounts result in optimum growth and yield without
wasting fertilizer or encouraging luxury consumption of nutrients, which can negatively impact
quality or cause fertilizer burn.

Recommendations based on soil tests and complemented with plant tissue analyses during the
season should result in the most efficient lime and fertilizer management program possible. Valid
soil sampling procedures must be used to collect the samples submitted for analyses, however.
To be beneficial, a soil sample must reliably represent the field or “management unit” from
which it is taken. Soil samples that are improperly collected, compiled or labeled are of dubious
benefit and may actually be detrimental. If you have questions about soil sampling, please contact
your local county extension office for information.

In addition to lime application, preplant applications and in-season supplemental applications of
fertilizer will be necessary for good crop growth and yield. In general, preplant applications are
made prior to installation of plastic mulch. Research shows that broadcasting over the entire field
is usually less effective than banding. An acceptable alternative to field broadcasting and one that
is most often used with plastic mulch production is the “modified broadcast” method, where the
preplant fertilizer containing a portion of the nitrogen and potassium, and any recommended
phosphorous and micronutrients, are broadcast in the bed area only.

For example, on a 72-inch wide bed, a swath (24 inches to 48 inches wide) of fertilizer is
uniformly applied centered over the bed and incorporated by roto-tilling. Additional applications
are then made through the drip irrigation system. In bareground culture, pre-plant applications are
followed by one to three side-dressed applications. The general crop requirements and
application timings for the various nutrients are discussed below.

Starter Fertilizer Solutions

Fertilizer materials dissolved in water and applied to the soil around plant roots at or just after
transplanting are called starter solutions. When proper formulations and rates are applied, they
can promote rapid root development and early plant growth. Starter solutions for tomatoes should
contain a high rate of phosphorus (approximate ratio of 1 Nitrogen:3 Phosphorus:0 Potassium is
common) and should be mixed and applied according to the manufacturer’s directions. Common
starter solutions consist of 3 pounds of a formulated material (such as 10-34-0, which weighs
approximately 11 lbs./gallon) mixed in 50 gallons of water. Approximately ½ pint of the starter
solution is normally applied per plant.

In addition to supplying phosphorus, which may be inadequately available (especially in cold
soils in the early spring), the starter solution supplies water and firms the soil around roots. This
helps eliminate air pockets that can cause root drying and subsequent plant or root damage. A
starter solution is no substitute for adequate rainfall or irrigation after transplanting, however.

Be careful to mix and apply starter fertilizer according to the manufacturer’s recommendations.
If the starter solution is too highly concentrated (mixed too strong), it can kill plant roots and
result in dead or stunted plants. When mixing and applying from a large tank, mix a fresh
solution only after the tank becomes empty. This helps prevent the gradual increase in concentration that will occur if a portion of the previous mix is used for a portion of the water
component in subsequent batches. If a dry or crystalline formulation is used, be sure it is
thoroughly mixed and agitated in the tank, since settling can result in streaks of highly
concentrated application that can stunt or kill plants.

Phosphorus and Potassium Recommendations

Table 4 indicates the pounds of fertilizer nutrients recommended for various soil P and K levels
according to University of Georgia soil test ratings of residual phosphorus (P2O5) and potassium
(K2O).

Note: If soil testing is done by a lab other than the University of Georgia
Soils Testing Laboratory, the levels recommended above may not apply
because of potentially different methodology and definition of fertility
ranges among labs.

All the recommended phosphorus should be incorporated into the bed prior to plastic mulch
installation or, for bare ground production, applied during or near transplanting. As previously
discussed, approximately ½ pint of a starter solution should be applied to each transplant.

For early growth stimulation in bare ground culture, pop-up fertilizer should be banded 2 to 3
inches to the side of the plants and 2 to 3 inches below the roots. Around 100 to 150 pounds per
acre of a pop-up fertilizer promotes earlier growth, particularly in cool/cold soils. A good pop-up
fertilizer has approximately a 1 to 3 N to P ratio. It should be relatively high in phosphorus and
low in potassium.

One-third to one-half of the potassium should either (1) be incorporated into the bed prior to
installing plastic mulch, or (2) be applied in two bands, each located 2 to 3 inches to the side and
2 to 3 inches below the level of plant roots for bare ground production. The remainder of the
recommended potassium should be applied through the drip system according to the schedule in
Table 5 or, for bare ground culture, in one to three applications as needed. It can be banded in an
area on both sides of the row just ahead of the developing root tips. The maximum number of
applications is usually more effective on sandy soils.

Nitrogen Recommendations

Typical Coastal Plains soils require a total of 150 to 200 pounds of nitrogen (N) per acre.
Extremely sandy soils may need additional N or an increased number of applications. Piedmont,
Mountain and Limestone Valley soils usually require only 100 to 150 pounds of N per acre for
tomato production.

For typical Coastal Plains soils, one-third to one-half of the recommended nitrogen should either
(1) be incorporated into the bed prior to plastic installation or, (2) with bare ground culture,
applied in two bands, each located 2 to 3 inches to the side and 2 to 3 inches below the level of
plant roots. Apply the remaining recommended N through drip irrigation according to the
schedule in Table 5. On bare ground, one to three side dressed applications (possibly four to five
applications for extended harvest period on very sandy soil) are needed. It can be banded in an
area on both sides of the row just ahead of the developing root tips. For heavier Piedmont,
Mountain and Limestone Valley soils, one to two applications are usually sufficient.

Table 5. An example fertilizer injection schedule for a Coastal Plains soil that is low in potassium. The schedule is for a 14-week crop. Extended harvests will require additional injection applications.

Nutrient

Total
(lbs/A)

Preplant
(lbs/A)

Crop Stage in Weeks (lbs/A/day)

1-2

3-4

5-6

7-10

11-12

13-14

Nitrogen

225

50

1.0

1.5

2.0

2.5

2.0

1.0

Potassium

225

50

1.0

1.5

2.0

2.5

2.0

1.0

Approximately 50 percent of the total applied N should be in the nitrate form. High rates of
ammoniacal nitrogen may interfere with calcium nutrition and result in an increased incidence of
blossom-end rot (BER). Side dressing with calcium nitrate as the nitrogen source often
significantly reduces the severity of BER.

Magnesium, Sulfur, Zinc and Boron Recommendations

If the soil test indicates magnesium is low and if lime is recommended, apply dolomitic
limestone. If magnesium is low and lime is not recommended, apply 25 pounds of elemental
magnesium per acre. Apply a minimum of 10 pounds of sulfur per acre and, if soil test indicates
low, apply 1 pound of actual boron per acre and 5 pounds of actual zinc per acre. These nutrients
should be supplied in the pre-plant fertilizer application.

Foliar Application of Fertilizer

The fact that plants can absorb some fertilizer elements through their leaves has been known for
some time. Leaves of many vegetable plants, however, are not especially well adapted for
absorbing nutrients because of a waxy cuticle. In some instances, plants that seem to benefit from
foliar uptake are actually benefitting from nutrient spray that reaches the soil and is taken up by
roots.

The effectiveness of applying macronutrients such as nitrogen, phosphorus and potassium to
plant leaves is questionable. It is virtually impossible for tomato plants to absorb enough N, P or
K through the leaves to fulfill their nutritional requirements; furthermore, it is unlikely that they
could absorb sufficient amounts of macronutrients to correct major deficiencies. Although
nitrogen may be absorbed within 24 hours after application, up to f4 days are required for
potassium uptake, and 7 to 15 days are required for phosphorus to be absorbed from foliar
application.

The crucial question is whether or not foliar N, P or K actually increases yield or enhances
quality. Although some growers feel that foliar fertilizer should be used to supplement a soil
applied fertilizer program, research findings do not support this practice. If proper fertilizer
management of soil applied nutrients is used, then additional supplementation by foliar
fertilization is not usually required.

Foliar nutrients are often expected to cure a variety of plant problems, many of which may be
unrelated to nutrition. They include reducing stress induced blossom drop, aiding in healing frost
or hail damaged plants, increasing plant resistance to various stresses and pests, etc. Nutrients are
only effective as long as they are supplying a nutritional need, but neither soil-applied nor
foliar-applied nutrients are panaceas.

Quite often after frost or hail occurs, tomato growers apply foliar nutrients to give the plants a
boost to promote rapid recovery. If a proper fertilizer program is being used before foliage
damage, tomato plants don’t need additional fertilizer. What they do need is time and the proper
environment for the normal recovery processes to occur. In addition, the likelihood of significant
nutritional benefits from a foliar application of fertilizer to plants that have lost most of their
leaves (or have a large proportion of their leaves severely damaged) is questionable.

Foliar application of sulfur, magnesium, calcium and micronutrients may help alleviate
deficiencies. They should be applied, however, only if there is a real need for them and only in
quantities recommended for foliar application. Application of excessive amounts can cause
fertilizer burn and/or toxicity problems.

Foliar applications of calcium nitrate or calcium chloride (one to three weekly applications
beginning at first bloom or at first sign of BER) may reduce the incidence of blossom-end rot
(BER), but there is little evidence indicating this is an effective practice. If attempted, the
recommended rate is 3 to 4 pounds in 100 gallons of water per acre.

Two to three foliar applications of water soluble boron (approximately 1 to 2 ounces by weight of
actual boron per application) at weekly intervals coinciding with flowering has in some instances
enhanced fruit set. A commercial formulation that contains both boron and calcium (2 to 3
ounces by weight of calcium per application) may be applied. Follow manufacturer’s directions
when applying any commercial calcium/ boron formulations.

Plant Tissue Analysis and Petiole Sap Analysis

Plant tissue analysis or petiole sap analysis is an excellent tool for measuring the nutrient status
of the crop during the season. Particularly with fertigation, it is simple to adjust fertilizer
injection rates according to the analysis results. Sufficiency ranges for tissue analysis are in
Tables 6 and 7 and are for first flower stage and first ripe fruit stage, respectively, with the
sample taken from the most recently mature leaf. Fresh sap can be pressed from the petioles of
tomato plants and used to determine nitrogen and potassium nutritional status. Sufficiency ranges
for these are listed in Table 8.

Table 6. Plant tissue analysis ranges for various elements for tomato sampled at the first flower stage with most recently mature leaves.

N

P

K

Ca

Mg

S

Fe

Mn

Zn

B

Cu

Mo

Status

Percent

Parts per Million

Deficient <

2.8

0.2

2.5

1.0

0.3

0.3

40

30

25

20

5

0.2

Adequate

2.8-4.0

0.2-0.4

2.5-4

1.0-2.0

0.3-0.5

0.3-0.8

40-100

30-100

25-40

20-40

5-15

0.2-0.6

High >

4

0.4

4

2

0.5

0.8

100

100

40

40

15

0.6

Table 7. Plant tissue analysis ranges for various elements for tomato sampled at the first ripe fruit stage with most recently mature leaves.

N

P

K

Ca

Mg

S

Fe

Mn

Zn

B

Cu

Mo

Status

Percent

Parts per Million

Deficient <

2.0

0.2

2.0

1.0

0.25

0.3

40

30

20

20

5

0.2

Adequate

2.0-3.5

0.2-0.4

2.0-4

1.0-2.0

0.25-0.5

0.3-0.6

40-100

30-100

20-40

20-40

5-10

0.2-0.6

High >

3.5

0.4

4

2

0.5

0.6

100

100

40

40

10

0.6

Table 8. Sufficiency ranges for petiole sap tests for tomato at various stages of crop development.

Sprayers

Paul E. Sumner, Extension Engineer

The equipment used for applying liquid insecticides, fungicides, herbicides and foliar fertilizers
are classified as sprayers. Basically, there are two types of sprayers recommended for spraying
tomatoes — hydraulic and air-curtain boom. The key to maximum coverage with insecticide and
fungicides is the ability of the air within the plant canopy to be replaced with pesticides.

Figure 1. Air-assisted boom sprayer.

The air-curtain booms (Figure 1) are designed with an external blower fan system. The blower
creates a high velocity of air that will “entrain” or direct the spray solution toward the target.
Some sprayers provide a shield in front of or behind the conventional spray pattern, protecting
the spray from being blown off-target.

The concept of this approach is to increase the effectiveness of pest-control substances, provide
better coverage to the underside of leaves, promote deeper penetration into the crop canopy,
make it easier for small droplets to deposit on the target, cover more acres per load, and reduce
drift.

Studies conducted by the USDA Agricultural Research Service in Stoneville, Mississippi, have
shown that the air-assisted sprayers tended to show improved insect control in the mid to lower
canopies. The air stream tended to open the canopy and help spray particles penetrate to a deeper
level. Mid- to lower-canopy penetration and coverage is important when working with
insecticides and fungicides, but may not be as critical when applying herbicides.

Figure 2. Hydraulic boom sprayer.

The hydraulic boom sprayers (Figure 2) get their name from the arrangement of the conduit that
carries the spray liquid to the nozzles. Booms or long arms on the sprayer extend across a given
width to cover a particular swath as the sprayer passes over the field. Each component is
important for efficient and effective application.

Most materials applied by a sprayer are a mixture or suspension. Uniform application demands a
uniform tank mix. Most boom sprayers have a tank agitator to maintain uniform mixture. The
agitation (mixing) may be produced by jet agitators, volume boosters (sometimes referred to as
hydraulic agitators) and mechanical agitators. These can be purchased separately and put on
sprayers. Make sure an agitator is on every sprayer. Some growers make a mistake of not
operating the agitator when moving from field to field or when stopping for a few minutes.
Always agitate continuously when using pesticides that tend to settle out.

Nozzles

Nozzle tips are the most neglected and abused part of the sprayer. Since clogging can occur when
spraying, clean and test nozzle tips and strainers before each application. When applying
chemicals, maintain proper ground speed, boom height and operating pressure.

This will ensure proper delivery of the recommended amount of pesticide to the plant canopy.

Herbicides

The type of nozzle used to apply herbicides is one that develops large droplets and has no drift.
The nozzles used for broadcast applications include the extended range flat fan, drift reduction
flat fan, turbo flat fan, flooding fan, turbo flooding fan, turbo drop flat fan and wide angle cone
nozzles. Operating pressures should be 20 to 30 psi for all nozzles except drift reduction and
turbo drop flat fans, flooding and wide angle cones. Spray pressure more than 40 psi will create
significant spray drift with flat fan nozzles. Operate drift reduction and turbo drop nozzles at 40
psi. Operate flooding fan and wide angle cone nozzles at 15 to 18 psi. These nozzles will achieve
uniform application of the chemical if they are uniformly spaced along the boom. Flat fan
nozzles should overlap 50 to 60 percent.

Insecticides and Fungicides

When applying insecticides and fungicides, use solid or hollow cone type nozzles. The two
patterns that are developed by solid or hollow cone nozzles can be produced by different tip
configurations. One type tip, disc-n-core, consists of two parts. One part is a core (swirl plate)
where the fluid enters and is forced through tangential openings. Then a disc-type hardened
stainless steel orifice (opening) is added. Another type of tip that produces the same patterns is of
one-piece construction (nozzle body). Liquid is passed through a precision distributor with
diagonal slots that produce swirl in a converging chamber. The resulting pattern of both tip
configurations is either solid or hollow cone. Even fan and hollow cone nozzles can be used for
banding insecticide or fungicides over the row.

Nozzle Arrangements

Figure 3. Use one nozzle over the row up to 8 inches, then change to three nozzles for optimum coverage of the tomato plant.

Figure 4. Add more pairs of nozzles as the plants grow taller and thicker.

When applying insecticides and fungicides, it is advantageous to completely cover both sides of
all leaves with spray. When spraying tomatoes, use one or two nozzles over the top of the row
(up to 8 inches wide). Then as the plants start to grow and bush, adapt the nozzle arrangement for
the various growth stages of plants (Figures 3 and 4). Opposing nozzles should be rotated
clockwise slightly so that spray cones do not collide. This will guarantee that the spray is applied
from all directions into the canopy. As the plant increases in height, add additional nozzles for
every 8 to 10 inches of growth. In all spray configurations, the nozzle tips should be 6 to 10
inches from the foliage. Properly selected nozzles should be able to apply 25 to 125 gallons per
acre when operating at a pressure of 60 to 200 or higher psi. Usually, more than one size of
nozzle will be needed to carry out a season-long spray program.

Diseases

David B. Langston, Jr., Extension Plant Pathologist

Plant diseases are one of the most significant limiting factors to tomato production in Georgia.
The hot, humid climate coupled with frequent rainfall and mild winters favor the development of
many pathogens and the diseases they cause.

Bacterial Diseases

Figure 5. Leaf lesions caused by bacterial spot.

Figure 6. Chlorotic leaves caused by bacterial spot.

Figure 7. Fruit lesions from bacterial spot.

Bacterial spot is the most common and often the most serious disease affecting tomatoes in
Georgia. This disease is caused by the bacterium Xanthomonas axonopodis pv. vesicatoria.
Bacterial spot lesions can be observed on leaves, stems and fruit and occurs during all stages of
plant growth. Leaf lesions usually begin as small water-soaked lesions that gradually become
necrotic and brown in the center (Figure 5). During wet periods the lesions appear more water-soaked. Lesions generally appear sunken on the upper surface and raised on the lower surface of
infected leaves. During periods of favorable weather, spots can coalesce and cause large areas of
chlorosis (Figure 6). Premature leaf drop is the ultimate result of leaf infection. Fruit lesions
appear as small, round, dark brown to black spots (Figure 7).

The bacterium is primarily seed-borne and most epidemics can be traced back, directly or
indirectly, to an infected seed source. Infected seedlings carry the disease to the field, where it
spreads rapidly during warm, wet weather. Workers working in wet fields can also be a major
source of disease spread.

All tomato seed planted for transplants, or direct seeded field grown tomatoes, should be tested
by a reputable seed testing company. Transplants should be inspected for bacterial spot lesions
before being sold or planted in the field.

Prevention is the best method for suppressing losses to bacterial spot. Purchase seed from
companies that produce the seed in areas where the disease is not known to occur. Hot water seed
treatment can also be used, and tomato seed can be soaked in water that is 122 degrees F for 25
minutes to kill the bacterium. Transplant production should take place in areas away from
commercial production to avoid contamination from production fields or vice versa.

Unlike pepper, tomatoes have little to no commercially available cultivars resistant to bacterial
spot. Rotate away from fields where tomatoes have been grown within the past year and use
practices that destroy volunteer plants that could allow the disease to be carried over to a
subsequent crop. Cull piles should be located away from production fields or transplant houses.
Copper fungicides used in conjunction with maneb will suppress disease losses if applied on a
preventive schedule with a sprayer that gives adequate coverage. Other bacterial-spot
suppressive treatments are also available.

Bacterial wilt, caused by Ralstonia solanacearum, is a devastating bacterial disease of tomatoes
worldwide. This bacterium can last in the soil for several years and has been responsible for
taking whole fields out of production. Bacterial wilt is recognized by a rapid wilting of the
tomato plant, often while the plant is still green (Figure 8). Wilted plants will eventually die. A
quick diagnostic tool is to cut a lower stem of a suspected infected plant and place it in a clear
vial or glass of water and watch for the opaque, milky bacterial streaming that comes from the
cut area (Figure 9).

Bacterial wilt is not easily controlled by fumigation or chemical means. There are few
commercially available cultivars with resistance to bacterial wilt. The best control tool is to rotate
away from infested fields for several years.

Bacterial speck, caused by Pseudomonas syringae pv. tomato is more of a problem of the cooler
growing regions in north Georgia but rarely has been a problem in south Georgia. Leaflet lesions
are very small, round and dark brown to black. During favorable weather the lesions can coalesce
and kill larger areas of leaf tissue. Bacterial speck causes oval to elongated lesions on stems and
petioles. Tomato fruit may have minute specks with a greener area surrounding the speck.
Control measures are similar to bacterial spot.

Virus Diseases

Virus diseases have been a severe limiting factor in tomato production in Georgia for several
years. Most virus diseases cause stunting, leaf distortion, mosaic leaf discoloration, and spots or
discoloration on fruit. The distribution of virus-infected plants is usually random with
symptomatic plants often bordered on either side by healthy, non-symptomatic plants. Virus
diseases are almost always transmitted by insect vectors, and the severity of a virus disease is
usually tied to the rise and fall in the populations of these vectors from season to season and
within a given season.

Some virus diseases are seed and mechanically transmitted. Only the viruses that have been the
most problematic on tomato in Georgia will be covered in this section.

Figure 10. Plants on left stunted by TSWV.

Figure 11. TSWV ring-spots on foliage.

Figure 12. Dark streaks caused by TSWV.

Figure 13. Chlorotic spots caused by TSWV.

Tomato spotted wilt virus (TSWV) is one of the most common viruses affecting tomato in the
southeastern United States. This virus is transmitted by thrips and can affect tomato at any stage
of development. The extensive host range of TSWV in weeds allows for a continual source of
inoculum for infection. As with any virus disease, however, early infections tend to cause more
yield losses than those occurring later in plant development. TSWV causes plant stunting (Figure
10), ringspots (Figure 11) and bronzing on infected plants. Tomato fruit produced on infected
plants may be misshapen, have dark streaks (Figure 12) or have chlorotic spots (Figure 13).
TSWV in Georgia tomato has been suppressed through the use of metalized plastic and other
colored mulches as well as resistant varieties.

Cucumber mosaic virus (CMV) is a very common disease of tomato and can be very
devastating where it occurs. This virus is transmitted by aphids and can be maintained in several
weed species that surround production fields. The characteristic symptoms for CMV are severely
stunted, distorted and strapped (faciated) leaves, stems and petioles. Symptoms of CMV often
resemble phenoxy herbicide injury. Few options are available for suppressing losses to CMV, but
destruction of weed hosts that harbor the virus will aid help suppress disease spread.

Tomato yellow leaf curl virus (TYLCV) is a very serious virus disease that has only recently
caused losses in Georgia. This is a virus that is whitefly-transmitted and is only a problem in
years when whitefly populations are high. Infected plants appear to be severely stunted and little
to no yield can be obtained from these plants (Figure 14). Plant symptoms appear as severely
stunted individual plants with greatly reduced leaves that take on a mouse-eared appearance
(Figure 15). Tomato leaflets of infected plants may also have a distinct marginal chlorosis
(Figure 16).

This disease is often brought in on infected transplants and then spread by whiteflies, so
transplant inspection is a must. Identifying infected plants soon after transplanting and removing
them will help prevent secondary spread. Preventive, systemic insecticide applications may
prevent disease spread as well.

Fungal Diseases

Figure 17. Leaf lesions from early blight.

Early blight caused by Alternaria solani is the most common fungal disease of tomato foliage
in Georgia. Leaf symptoms appear as round to oblong, dark brown lesions with distinct
concentric rings within the lesion (Figure 17). Lesions are generally surrounded or associated
with a bright yellow chlorosis. Stem lesions are slightly sunken, brown and elongated with very
pronounced concentric rings. Fruit may become infected around the calyx, and a velvety spore
mass can often be observed on fruit lesions. The disease is introduced by wind or rain-splash and
is carried over to subsequent crops on infested debris.

Wet, humid weather favors disease development. In the field, the fungus spores are spread
mainly by wind. Unless controlled, it causes severe defoliation. Resistant varieties are available
to avoid losses to early blight. Rotation and deep turning are important for reducing initial
inoculum. The disease is easily controlled with chemical sprays. Spray programs used for
bacterial leaf spot will suppress early blight, but the addition of chemicals specifically targeted at
early blight should be incorporated into the spray program.

Late blight caused by Phytopthora infestans. This is probably one of the best known tomato
diseases worldwide, but it is a rare in Georgia except for occasional epidemics observed in north
Georgia. This disease causes dark, water-soaked, greasy lesions on stems and foliage. A whitish-gray, fuzzy sporulation can be seen on the undersides of leaf lesions and directly on stem lesions
during periods of high moisture. A soft rot of fruit can also be observed.

Phytopthora is a fungal-like organism that is in a separate kingdom than the fungi. It is a water-mold, oomycete organism that has a mobile swimming-spore stage as part of its life cycle. The
pathogen is carried by wind to non-infested areas, where it remains in the soil and on infested
plant debris until favorable weather and a new host crop coincide to create a new epidemic.
Warm days and cool nights coupled with adequate moisture favor the spread and infection of the
late blight pathogen.

Plant resistance to this disease is available but does not play a major role in disease control.
Destroying plant debris and rotating away from fields with a history of the disease is a must.
Preventive fungicide sprays are generally relied on heavily where this disease occurs as a yearly
problem.

Septoria leaf spot (Septoria lycopersici) and Target spot (Corynospora cassiicola) are foliar
fungal diseases of some importance in Georgia but are not generally a problem with the current
spray regime that is targeted at early blight and bacterial spot.

Fusarium wilt caused by Fusarium oxysporum f.sp. lycopersici. Fusarium wilt is a soilborne
disease of tomatoes that is generally a problem in specific fields where the pathogen has been
introduced. The disease is initially brought into a field on infested seed, plant stakes, transplants
or infested soil on equipment.

Figure 18. Complete yellowing and wilting from Fusarium wilt.

Figure 19. Vascular discoloration from Fusarium wilt.

Symptoms usually appear during hot weather and after fruit set has begun. Symptoms appear as a
yellowing and wilting on one side of the plant at first, usually during the hottest part of the day,
followed by the eventual complete yellowing and wilting of the plant (Figure 18). Entire death of
the plant is the final result. Vascular discoloration is often observed on stems above the soil line
(Figure 19).

This fungus can stay in the soil in a resting state for several years, and rotation away from these
fields for 5-7 years will lessen the severity but will not completely eliminate the disease.
Fumigation really only delays disease onset and may lessen the total disease incidence.
Preventing the disease from getting into the field is the best control measure, followed by the use
of resistant varieties. Several races of this disease occur, however, and resistance must be specific
to the race of Fusarium that is in the field in question.

Southern stem blight caused by Sclerotium rolfsii. This is a common destructive disease of
tomatoes in Georgia. Since most tomatoes are rotated with peanuts, soybeans and other
susceptible crops, the disease has become a major problem. The fungus attacks the stem of the
plant near or at the soil line and forms a white mold on the stem base. Later in the season, small,
round brown bodies appear in the mold (Figure 20). Infected plants wilt and slowly die. Vascular
discoloration can be observed on stem tissues above the lesion.

The severity of the disease can be lessened by following good cultural practices: rotation, litter
destruction and deep turning with a moldboard plow are the best cultural defenses against this
disease. Fumigation as well as at-plant and drip-applied fungicides are also effective in reducing
losses to southern stem blight.

Nematodes

Root-knot nematodes (Meloidogyne spp) can cause serious economic damage to tomatoes.
These tiny worms live in the soil and feed on the roots of tomatoes. Not only do they cause
physical damage that interferes with the uptake of water and nutrients, but they allow the
establishment of other diseases.

Nematode infected plants are generally stunted with pale green to light yellow foliage. Symptoms
may be temporarily masked by supplying additional fertilizer and water. Soils infested with root-knot nematodes should be avoided or treated with fumigant or chemical nematicides before
tomatoes are planted.

Insect Management

Alton N. Sparks, Jr., Extension Entomologist

Insect pests can damage tomato throughout the growing season, but severity varies with location
and time of year. While many insects that feed on tomato are only occasional pests in Georgia, a
few species are common pests and occur every season. The severity of damage to tomato by
insect pests is largely due to abundance of the pests, which is related to environmental
conditions. With most insects, outbreaks are difficult to predict, and it is even more difficult to
predict if control measures will be required. A knowledge of insect habits, careful pest
monitoring and timely use of effective control measures will enable growers to avoid or at least
reduce the damage they suffer. Tomato is well suited for insect pest management.

Because a variety of insects may attack tomato, scheduled sprays are frequently considered for
insect management. Scouting two to three times per week, however, allowing for early detection
of infestations and timely application of pest specific control measures, is the most cost-effective
management strategy. Possible exceptions to this are the management of thrips, which vector
Tomato Spotted Wilt Virus, or fields with a history of specific pest problems that require
preventive control or are difficult to manage with curative treatments.

When insecticidal control is determined to be necessary, use the Georgia Pest Management
Handbookto aid in selecting the correct insecticide for control of specific insect pests described
in the following text.

Seedling Pests

Cutworms

Young tomato transplants may be cut down just above the soil surface by cutworms.
While this damage is readily apparent, the insects are difficult to detect during the day as the
larvae typically hide in the ground. Detection of the insects and verification of the pest problem
is most easily accomplished when larvae are feeding at night.

The majority of cutworms pass the winter in the soil as full-grown larvae, and cutworm damage
can be particularly abundant in fields where grass sod was the previous crop or in previously
fallow fields with heavy weeds. Greatest damage is often found in wet areas of fields but can also
be concentrated on field margins where cutworms are moving in from adjacent areas.

Cutworms are generally considered a seedling pest, but they may also feed on foliage and fruit of
mature plants. Use preventive insecticide treatments on fields with a history of cutworms or on
tomato fields following grass sod. Where preventive treatments are not used, use directed sprays
for cutworm control when 5 percent of the seedlings have been damaged or destroyed and
cutworms are still present. All directed or foliar sprays used for cutworm control should be
applied late in the day when cutworms are active.

Other insects attacking the main stem of seedlings. Several occasional pests may cause
damage similar to cutworms. White grubs (immature stage of May beetles and June beetles) may
cut off plants, but they will typically cut plants slightly below the soil line as compared to
cutworms, which will usually cut at or slightly above the soil line.

Vegetable weevils, crickets and grasshoppers may also attack the main stems of seedlings.
Generally these pests do not cut off plants except for the smallest transplants. They tend to feed
up and down the main stem, removing the softer outer tissue, and can completely girdle the plant.
This damage generally causes plant death and, at the least, makes the plant susceptible to lodging
and seedling diseases.

Threecornered alfalfa hopper may also attack seedlings. This pest has piercing-sucking mouth
parts and does not remove plant tissue. It will circle small stems while feeding, producing a
“girdle” on the stem, which interferes with water and nutrient translocation. This weakened area
makes the plant susceptible to lodging.

Thrips

Thrips may be present in tomato fields throughout the growing season, but they are more
prevalent in the spring. Prior to plants blooming, tobacco thrips generally dominates the
population since this species readily feeds and reproduces on foliage. Flower thrips species
populations can increase dramatically once blooming and pollen availability increases. Flower
thrips populations may increase prior to the crop blooming if outside sources of pollen are
plentiful.

Figure 21. Adult thrip.

Plant injury is caused by both nymphs and adults (Figure 21) puncturing leaf and floral tissues
and then sucking the exuding sap. This causes reddish, gray or silvery speckled areas on the
leaves. With severe infestations, these areas can interfere with photosynthesis and result in
retarded growth. Heavy infestations during the bloom stage may cause damage to developing
fruit through egg laying. This damage appears as dimples with necrotic spots in the center and
may be surrounded by a halo of discolored tissue. Occasionally thrips aggregate on fruit well
hidden from sprays. This may result in russeting damage from continual feeding during fruit
development. While thrips can cause direct damage to foliage and fruit, their role as vectors of
tomato spotted wilt (TSWV) is of primary concern in Georgia.

To prevent direct damage, make applications of insecticides when 20 percent of plants show
signs of thrips damage, or when 5 or more thrips per bloom are found. Thrips are very small, so
close observation is necessary. Thrips may be monitored in a variety of ways including various
methods of beating plants to dislodge thrips from foliage into a collection device (Styrofoam cup,
white tray, sticky trap). An effective in-field survey method for thrips in blooms is to place
several blooms in a vial of alcohol and count the thrips as they die and settle to the bottom.

Where TSWV is of concern, grow virus resistant varieties. For management of TSWV in
susceptible varieties, UV-reflective plastic mulch, or metalized mulch, has proven useful in
suppression of thrips populations and virus incidence. Insecticides also are frequently used in a
preventive manner where TSWV is of concern.

Foliage Feeders

Aphids

Figure 22. Adult winged aphid.

Aphids or plant lice are small, soft-bodied insects that may feed on tomato plants from
time of planting until last harvest. Aphids cluster in shaded places on leaves, stems and
blossoms. While winged migrants (Figure 22) move from field to field spreading virus diseases,
host plant resistance in tomatoes has helped minimize this problem. Large populations of aphids
on young plants can cause wilting and stunting but rarely occur. At harvest, infestations can
represent a contamination both through their presence and through production of honeydew,
which gives rise to sooty mold.

Establishment of aphid colonies on tomato is often reduced by wet weather, but during cool, dry
weather, large numbers of aphids may develop quickly. Feeding by these pests causes newly
formed leaves to be crinkled and malformed. Aphid populations can be assessed by examining
terminals and the undersides of leaves. Treatments for aphids in early spring plantings may be
postponed until distinct colonies of immature aphids are found on greater than 10 percent of the
plants. Aphids in late summer plantings are usually controlled by treatments for whiteflies.

Colorado Potato Beetle

Colorado potato beetles occasionally occur in damaging numbers in
tomato fields. They lay orange-yellow eggs in groups of a dozen or more on the undersides of
leaves; these eggs are often mistaken for lady beetle eggs. Injury to tomatoes is due to actual
consumption of foliage and stems by the chewing adults and larvae. Young plants may be
completely defoliated.

In tomato-growing areas where spraying for insect control is a regular practice, insecticides have
reduced the population so that it is no longer a serious problem. In some areas, however, the
control of this insect still demands attention. Colorado potato beetles can occur in large numbers
and are generally uniformly distributed over a local area. Because of their short life cycle and
high reproductive capacity, treatments are needed as soon as beetle eggs or larvae are found.
Because this is a rare pest, determine its presence by scouting.

Flea Beetles

Figure 23. Adult flea beetle.

The name flea beetle applies to a variety of small beetles with enlarged hind legs,
which jump vigorously when disturbed. Their injury consists of small, rounded or irregular holes
eaten through or into the leaf. The most common flea beetles are about 1/16 inch long and nearly
a uniform black in color (Figure 23).

Flea beetles may attack tomatoes at any time during the growing season but are often most
numerous and of greatest concern early in the season. Apply insecticides for control of flea
beetles when flea beetles become numerous and defoliation is greater than 10 percent. Flea
beetles generally do not require control once plants are beyond the 5 leaf stage.

Hornworms

Figure 24. Hornworm larva.

Hornworms are large, green cater-pillars with white diagonal markings. They reach
a length of 3 inches. The most distinguishing characteristic of hornworms is the slender horn
projecting back-ward from the rear of the body (Figure 24). Hornworms may feed on green fruit,
but they primarily feed on the foliage of tomato plants and may cause enough defoliation to allow
sun scald of fruit. The adult moths deposit spherical translucent eggs, singly, on the undersides of
leaves. Apply treatments for hornworm control when one larva is found on 4 percent of the
plants examined.

Cabbage Looper

Figure 25. Cabbage looper larva.

The most common looper in tomatoes in Georgia is the cabbage looper
(Figure 25). Loopers are foliage feeders and damage to fruit is rare. Larvae chew irregular holes
in leaves. Leaf damage is of concern only when large numbers of larvae attack small plants or if
feeding is extensive enough to open the canopy to expose fruit to sunburn. Mature plants can
tolerate multiple larvae per plant without significant loss.

Looper eggs are laid singly on plants and can be confused with tomato fruitworm eggs; however,
looper eggs are flatter than fruitworm eggs and have finer ridges radiating from the top of the
egg. Looper larvae are easily identified by their habit of arching their backs into a loop as they
crawl. Loopers are frequently controlled by insecticide applications applied for other caterpillar
pests.

Leafminers

Figure 26. Winding mines in leaf created by leafminers.

Adult leafminers are tiny, shiny, black flies with yellow markings. Adult female
flies lay eggs within the leaves, and white to pale yellow larvae with black mouthparts mine
between the upper and lower leaf surface for about 5 to 7 days before dropping to the ground to
pupate. As the larvae grows and consumes more leaf tissue, the winding mine increases in
diameter. Leafminer infestations usually are first detected as these slender, white, winding trails
caused by the larvae (Figure 26). The leaves are greatly weakened and the mines may serve as
points where decay and disease may begin. With severe infestations, heavy leaf loss may lead to
sun scald of fruit.

Several parasites attack this pest and can keep leaf-miner populations under control. Leafminers
rarely pose a serious threat to tomato production in Georgia except in fields where their natural
enemies are reduced by early, repeated insecticide applications. Begin treatments for leafminer
control when populations reach an average of five mines/leaf with at least 25 percent of the
mines containing live larvae.

Spider Mites

Figure 27. Adult spider mites and eggs (highly magnified).

Figure 28. Speckled leaf caused by spider mites.

Spider mites appear to be developing into a more consistent pest in south Georgia.
They generally feed on the underside of leaves, but can cover the entire leaf surface when
populations are high. The minute eight-legged mites appear as tiny, reddish, greenish or yellow
moving dots on the undersides of leaves (Figure 27. Because of their size, the first detection of
spider mite infestations is usually damage to the leaves. Leaves of tomato plants infested with
spider mites are initially lightly stippled with pale blotches (Figure 28). In heavy infestations, the
entire leaf appears light in color and dries up, often turning reddish-brown in blotches or around
the edge and may be covered with webbing.

Greatest damage to tomatoes occurs during dry, hot weather, which is favorable for development
of extremely large mite populations. Spider mites are also generally considered a secondary pest,
with damaging populations frequently occurring after application of broad spectrum insecticides.

To check for spider mites, observe plant foliage for characteristic damage. Look on the
undersides of leaves for mites. Pay close attention to field borders and weedy areas. Mites
frequently get started and reach their highest density along field margins adjacent to roads where
the plants are covered with dust.

In general, apply treatments for mite control when mites become numerous and their damage
appears excessive. Some of the newer acaricides, however, are slow acting or effective only on
selective stages of mites. If these acaricides are used, a more preventive approach to management
is required. Where a history of mite problems exists, this preventive approach may be justified in
tomatoes, which are favored hosts of spider mites.

Whiteflies

Figure 29. Sweetpotato whitefly nymphs on the underside of a leaf.

Adult whiteflies are tiny (about ⅛ inch) insects with white wings, a yellow body and
piercing-sucking mouthparts. Adults are found on the underside of leaves, where they feed and
lay eggs. While adults can cause direct damage by feeding, typically the nymphs are the more
damaging stage. The scale-like nymphs (Figure 29) also occur on the underside of leaves and all
but the first instar are sessile.

Whiteflies, particularly the sweetpotato or silverleaf whitefly, can be a severe pest in tomatoes
grown in the fall. Because this pest does not overwinter well in south Georgia, tomatoes grown in
the spring typically are harvested before whitefly populations reach damaging levels. The
sweetpotato whitefly can cause direct damage in the fall, when populations are large enough to
cause defoliation, and can produce enough honeydew and sooty mold to be a contamination
problem at harvest. At much lower densities, however, this pest causes irregular ripening of fruit
and can transmit severe viral diseases, including tomato yellow leaf curl.

Whiteflies typically are not a problem in tomatoes grown in the spring. Preventive treatments
with systemic soil-applied insecticides are generally necessary for tomatoes grown in the fall, and
may require additional foliar treatments.

Fruit Feeders

Tomato Fruitworm (corn earworm)

Figure 30. Late instar fruitworm larva.

Figure 31. Early instar fruitworm larva.

Among the most serious pests of tomatoes is the tomato
fruitworm or corn earworm, particularly in the summer and fall. The larvae vary greatly in color
from a light green to brown or nearly black and are lighter on the underside (Figure 30). They are
marked with alternating light and dark stripes running lengthwise on the body. Early instar larvae
have stout hairs, which gives them a somewhat spiny appearance as compared to the smooth skin
of most other caterpillars found on tomatoes (Figure 31).

Eggs are laid singly on the terminals or close to flowers or small fruit. The eggs hatch in 3 to 5
days, and the larvae can attack buds and fruit shortly after hatching. If fruiting structures are not
available, the larvae can feed on foliage. The larva are rather restless and shift from one fruit to
another so a single caterpillar may spoil several fruit without eating the equivalent of a single
fruit. This movement does benefit control efforts, as the caterpillars are exposed to insecticide
applications as they move among fruit. Several generations of tomato fruitworm may develop
each year. Apply treatments for tomato fruitworm control when 1 percent of fruit are infested
with larvae or if eggs are easily found.

Beet Armyworms

Figure 32. Late instar beet armyworm.

Figure 33. Beet armyworm egg mass hatching.

Beet armyworm (Figure 32) appears to be becoming a more consistent pest.
Historically, it is considered a secondary pest, with large populations usually occurring only after
multiple applications of broad spectrum insecticides. This pest is now a fairly consistent pest in
the summer and fall, however.

Beet armyworms feed on both the foliage and fruit of tomato plants. Eggs are laid in masses on
the undersides of foliage. Young larvae remain near the site of hatching (Figure 33), feeding in
groups that cause characteristic foliar damage referred to has “hits.” After feeding on foliage for a
few days, medium sized larvae (3rd instar) may migrate to the fruit. They may tunnel into the fruit
under the calyx or eat directly through the fruit wall.

Because beet armyworms start as foliage feeders, treatments can be delayed until hits are
detected but should be applied prior to third instar. In practice, treatments are generally begun
with first detection of egg masses or hits.

Other Armyworms

Figure 34. Yellowstriped armyworm larva.

Both Southern armyworm and Yellowstriped armyworm are commonly
encountered defoliators of tomatoes. Their behavior is similar to the beet armyworm, with eggs
laid in masses, early instars feeding gregariously on foliage, and later instars feeding on foliage or
fruit. The Southern armyworm is more prevalent than the Yellowstriped armyworm, but both are
occasional pests. Larvae of both species have two lines of dark triangular marks on their backs
and a longitudinal white to yellow line along each side (Figure 34). Yellowstriped armyworm
seldom reach population densities that require treatment, but can be difficult to control. Large
outbreaks of southern armyworm can occur, but this pest is easily controlled with insecticides.
Insecticides targeted at other caterpillar pests likely prevent more frequent damage by southern
armyworm.

Tarnished Plant Bugs

Tarnished plant bugs are sucking bugs that primarily attack the young
flower buds causing them to abort. Young flower buds turn yellow to black after tarnished plant
bug feeding. Infestations may be heavy in spring plantings and fruit set can be poor if the bugs
are not controlled.

Both nymphs and adults feed on tomato. The nymphs are difficult to find unless high numbers
are present. Scouting for the adults is relatively simple. Visually examine plants and treat if one
adult per six plants is found.

Stink Bugs and Leaffooted Bugs

Figure 35. Southern green stink bug adult.

Figure 36. Southern green stink bug nymph (late instar).

Figure 37. Leaffooted bug adult.

Several species of stink bugs can damage tomatoes. Stink bug
adults are generally medium sized shield-shaped bugs with broad “shoulders” and a bluntly
rounded abdomen (Figure 35). They also have a triangular shaped shield on their backs. The
most common species in tomatoes are either a uniform green color (southern green stink bug) or
tan to brown with light colored undersides (various species of brown stink bugs). Stink bug
nymphs are more oval shaped (Figure 36) and vary greatly in color. Eggs are somewhat barrel-shaped and are deposited on end in tightly packed clusters. Leaffooted bugs are brown, medium
sized bugs which get their common name from the flattened leg segment of the hind leg, which
gives this segment a leaf-like appearance (Figure 37).

Stink bugs and leaffooted bugs have needle-like mouthparts with which they puncture plant
tissue and remove sap. The greatest damage results from feeding on fruiting structures. Severity
of the damage to fruit varies greatly with the developmental stage of the fruit. Damage early in
fruit development can lead to severe deformities and abscission, while damage near harvest may
result in small dark spots at the feeding site. These insects may also introduce bacteria and yeast
as they feed, or may simply provide a site of entry for disease organisms, resulting in fruit decay.
Stink bugs have become more of a problem in Georgia in recent years.

Tomato Pinworm

Figure 38. Tomato pillworm larva and damage (calyx of fruit removed).

Tomato pinworms are small moths with a somewhat speckled appearance.
Damage is caused by the caterpillar, which appears smooth-skinned with a purplish appearance
in older larvae (Figure 38). Larvae usually begin feeding in leaf mines before moving to fruit but
may enter fruit soon after hatching. In leaves, larvae mine for the first two instars, then form leaf
folds in which the last two instars are completed. The most important damage occurs when larvae
enter fruit. Larvae may enter fruit of any maturity. Larvae generally bore into fruit under the
calyx, and the entry holes are difficult to detect. Once larvae have been feeding for a while,
brown granular frass can often be seen at the edge of the calyx. Larvae may feed shallowly
beneath the skin of the fruit near the stem or may bore into the core of the fruit. The feeding creates narrow blackened tunnels and exposes fruit to decay. It is difficult to sort out
infested fruit, and larvae present at harvest may create a contamination problem. Adults can be
monitored with pheromone traps, and pheromones have been used for mating disruption.

In Georgia, this is not a consistent pest; cultural controls, scouting and judicial use of pesticides
is recommended. Problems with pinworm frequently arise from use of infested transplants; use of
locally produced “clean” transplants is recommended to avoid transplanting pest problems with
the crop. Close scouting of the crop for leafmines and frass around the calyx should detect
populations before they reach damaging levels. In most cases in Georgia, this pest is likely
controlled by insecticide applications targeting other lepidopterous species.

Weed Control

A. Stanley Culpepper, Extension Agronomist — Weed Science

Effective weed management is one of many critical components of successful tomato production.
Weeds compete with tomato plants for light, nutrients, water and space as well as interfere with
harvesting practices. Additionally, weeds can harbor deleterious insects and diseases. If weeds
are left uncontrolled, severe infestations can reduce yield at least 50 percent even when tomatoes
are produced on plasticulture.

One of the most effective tools for suppressing weeds in tomatoes is a healthy, vigorous crop.
Good crop management practices that result in rapid tomato canopy development help minimize
the effects of weeds.

Site selection also can play a significant role in weed management. Rotation away from fields
infested with troublesome weeds such as nutsedge may minimize the presence of these weeds
and allow the use of alternative crops and control methods. Additionally, to prevent the spread of
weeds from field to field during harvest, clean equipment and personnel when moving from
heavily infested areas. This precaution can be of significant consequence in preventing or
minimizing the introduction of new weed species into “clean areas.”

Mechanical Control Methods

Mechanical control methods include field preparation by plowing or discing, cultivating,
mowing, hoeing and hand pulling of weeds. Most of Georgia’s tomatoes are produced on mulch,
limiting the practicality of most mechanical control methods. Of course, hoeing and hand pulling
of weeds are quite common.

For those growers producing tomatoes on bare ground, mechanical control practices such as
cultivation and primary tillage are very beneficial for managing weeds.

Mulching

The use of polyethylene mulch increases yield and earliness of vegetables. Mulches act as a
barrier to the growth of many weeds. Nutsedge, however, is one weed that can and will penetrate
through the mulch. Additionally, weeds that emerge in the transplant hole will greatly reduce
yield and quality of the crop, so fumigants and/or herbicides are often used in conjunction with
mulch.

Fumigants

Currently, methyl bromide is the fumigant of choice in tomato production because it is extremely
effective in controlling diseases, nematodes and weeds, and most growers are comfortable
applying this fumigant. Unfortunately, methyl bromide is being removed from the market place.
The University of Georgia has been and continues to conduct many research trials to find a
suitable alternative to methyl bromide.

Contact your local extension office for up-to-date information on alternatives to methyl bromide.
In general, fumigants are restricted-use chemicals and must be handled carefully by a certified
applicator. Apply all fumigants in full compliance with label recommendations and precautions.

Developing a Herbicide Program

Before selecting herbicides, growers should know what weeds are present or are expected to
appear, the soil characteristic (such as texture and organic matter content), the capabilities and
limitations of the various herbicides, and how best to apply each herbicide.

Weed Mapping

The first step in a weed management program is to identify the problem; this task is best
accomplished by weed mapping. Develop surveys each fall to provide a written record of the
species present and their population levels.

Proper weed identification is necessary since weed species respond differently to various
herbicides. For assistance in identifying weeds, contact your local county extension office.

In-Season Monitoring

Monitor fields periodically to identify the need for postemergence herbicides. Even after
herbicides are applied, continue monitoring to evaluate the success of the weed management
program and to determine the need for additional control measures.

Herbicides

Properly selected herbicides are effective tools for weed control. Herbicides may be classified
several ways, depending on how they are applied and their mode of action in or on the plant.
Generally, herbicides are either soil-applied or foliage applied. They may be selective or non-selective, and they may be either contact or translocated through the plant. For example, paraquat
(Gramoxone) is a foliage applied, contact, non-selective herbicide, while metolachlor (Dual)
usually is described as a soil-applied translocated, selective herbicide.

Foliage-applied herbicides may be applied to leaves, stems and shoots of plants. Herbicides that
kill only those parts of plants which the spray touches are con-tact herbicides. Those herbicides
taken into the plant and moved throughout the plant are translocated herbicides. Paraquat
(Gramoxone) is a contact herbicide, while glyphosate (Roundup) or sethoxydim (Poast) are
translocated herbicides.

For foliage-applied herbicides to be effective, they must enter the plant. Good coverage is
critical, and these products often require the addition of some type of adjuvant. Soil-applied
herbicides are either applied to the surface of the soil or incorporated into the soil. Lack of
moisture or rainfall following application of soil-applied herbicides often results in poor weed
control.

Many herbicides applied in Georgia offer residual weed control, which is beneficial in the crop
where the herbicide was applied. Before applying any herbicide in a crop, however, review the
herbicide label and obtain the needed information on rotation restrictions. Many herbicides
applied in peanut, cotton, tobacco and other vegetable crops can cause significant crop injury to
tomato planted the following year.

Stale Seedbed

Herbicide options in the tomato crop are limited. The use of a stale seedbed approach prior to
planting tomato on bareground or prior to transplanting tomato into mulch can be extremely
useful.

A stale seedbed approach is one where the weeds are allowed to emerge and then treated with a
non-selective herbicide (glyphosate or paraquat usually) prior to planting. Be extremely careful
when applying herbicides over the top of mulch prior to planting because some herbicides cannot
be successfully removed from mulch and may cause severe crop injury once the crop is planted.
Both glyphosate and paraquat, however, can be applied over mulch as long as a rain-fall or
irrigation event of at least 0.5 inch occurs after applying these herbicides but before planting.

The author would like to thank Alan C. York (N. C. State University) and Bill Stall (University
of Florida) for their contributions to this publication.

Harvest, Handling and Sanitation

William C. Hurst, Extension Food Scientist

Field Maturity

Fresh tomatoes are the number one crop in terms of farm gate value among all the vegetables
grown and harvested in Georgia. Tomatoes should only be harvested when they reach the
mature-green stage. If tomatoes are harvested any earlier, the fruit will fail to ripen normally.
Since the mature-green state is difficult to judge externally, growers will often take a
representative sample of fruit from their fields and cut it open for internal examination. A typical
mature-green tomato will have a jelly-like matrix in all locules, and seeds will be sufficiently
developed so as not to be cut when the fruit is sliced with a sharp knife.

While a few large commercial tomato operations harvest mature-green tomatoes that will be
ripened later with ethylene gas, most Georgia growers wait un-til about 10 percent of their field
reaches the “breaker” (pinking at the blossom end) stage of maturity before harvesting. Tomato
quality at harvest is primarily based on uniform size and freedom from growth or handling
defects. Appearance is a very important quality factor. Tomatoes should have a waxy gloss; small
blossom-end and stem-end scars that are smooth; presence of a brown corky tissue at the stem
scar; uniform color and minimum size for the variety; and an absence of growth cracks,
catfacing, zippering, sunscald, insert injury, hail damage, mechanical injury or bruising.

Size is not typically a factor of grade quality, but it may strongly influence commercial buyers’
expectations. Georgia growers strive to harvest only large and extra-large tomatoes.

Harvesting

Fresh market tomatoes are harvested by hand in Georgia. The harvesting operation varies
somewhat among growers. Mature-green harvested tomatoes are placed into polyethylene
picking buckets that are carried to a flatbed trailer where the fruit is dumped into plastic bulk
bins. Each bin holds between 800 and 1,200 pounds of fresh fruit, and the trailer is positioned in
the field so pickers only have to walk a minimal distance to reach a bin. Once all bins are loaded,
they are transported to a centralized packinghouse where the fruit is washed, sized and packed
out. Some growers avoid use of bulk bins because of potential damage to the fruit and field pack
tomatoes into boxes. Some growers also combine the two approaches, with field packing of
“pinks” (tomatoes that have begun changing color) and bulk harvesting of mature green
tomatoes.

Good harvesting management is needed to pick high quality tomatoes. Care must be taken when
harvesting “breaker” stage fruit because the riper the tomato, the more susceptible it is to
bruising. Harvest crews should carefully place fruits into picking containers instead of dropping
them. Research has demonstrated that a drop of more than 6 inches onto a hard surface can cause
internal bruising that is not evident until after the tomato is cut open.

Figure 39. Field heat retained in packed tomatoes can speed up the breakdown of fruit.

Bruising is characterized by water-soaked cellular breakdown of the cross-wall and locular (seed
cavity) area. External bruising will be caused if pickers hurl or dump tomatoes too vigorously
from the picking bucket into unpadded bulk bins. Bins should never be over-loaded because
excessive tomato weight will cause bruise damage due to compression. Harvested tomatoes must
be shaded to minimize heat-up while waiting for pallet bin dumping at the packinghouse.
Research has shown that bulk bin tomatoes held in the hot sun for just one hour can be as much
as 25 degrees F warmer than fruit held in the shade. Field heat can speed up breakdown after
packing (Figure 39).

Pickers should do preliminary grading to remove decayed fruit from the plants as they harvest the
field. This will prevent crossover disease contamination to otherwise healthy, sound fruit. Wet
tomatoes should never be harvested, because surface moisture increases field heat accumulations
in the load and enhances disease development.

All picking buckets should be cleaned and sanitized at the end of each harvest day to prevent the
potential accumulation of disease organisms from infecting sound fruit picked the next
production day. Rinse buckets with water to remove soil and field debris, then wash them in a
sanitizing solution consisting of 5 oz. of household bleach (5.25 percent sodium hypochlorite)
mixed in 5 gallons of water.

Postharvest Handling

The importance of care in handling tomatoes between the time of harvest and shipping to market
cannot be overemphasized, since about half of the cost of tomato production is in the grading,
cooling and packing of the product. Bulk bins of harvested tomatoes are taken from the field to
the packing house, where they are mechanically unloaded in a water dump tank or concrete pit.
Water jets convey the fruit by flume onto an inclined dewatering roller belt with soft bristle
brushes that remove field debris. The fruit is then dried, pre-graded, color sorted and sized before
being jumble-packed into 25-pound fiberboard cartons.

Georgia tomatoes typically are not waxed before shipping.

Mechanical damage (i.e., cuts, punctures, bruises, scars, scuff marks and discolored areas)
accounts for more defects at the shipping point and in the market than all other defects combined.
Of these, bruises are the most common and serious, comprising about half of all mechanical
damage. Bruised tomatoes may be flattened or indented and soft; the locules either are dry or, if
gelatinous tissue is present, it may be thick and stringy from continuous pressure or watery from
severe impacts.

When tomatoes are physically injured during handling, disease organisms can easily invade the
flesh, setting up decay. As shown in Table 9, decay due to bruising was the greatest contributor
to tomato loss in marketing channels (Ceponis and Butterfield, 1979).

Table 9. Wastage of fresh tomatoes in Greater New York retail stores and in consumer samples (1974-1977).

Location of loss
and type of
packaging

Causes of loss (% by weight)

Bruise
decay

Physical
injuries

Physiological
disorders

Total

Retail

Prepackaged

4.2ab*

1.5a

0.6a

6.3a

Loose

3.8b

2.0a

0.9a

6.7a

Consumer

Prepackaged

6.5a

1.1a

0.3a

7.9a

Loose

3.8a

0.7a

0.2a

4.7b

* Numbers followed by the same letter are not significantly different at 5% probability level.

Tomatoes are scuffed and scarred when they rub against rough surfaces, such as bin boxes, packout cartons, dirty sorting belts, or even against each other, particularly when dirty. Tomatoes
below about 60 degrees F scuff more easily than warm fruit. Scuffing and scarring are followed
by pitting and browning, because the injured tissue dries out.

Tomatoes may be bruised any time between field and kitchen by being (1) thrown into picking
box or bin; (2) pressed out of shape in a bin loaded too deeply; (3) dumped too vigorously from
box or bin onto sorting belt, or dropped too far from sorting belt to shipping container; (4)
squashed during stacking, loading or in transit; (5) handled roughly during sorting in the ripening room or during prepacking; (6) dumped into bulk retail display; or (7) squeezed in the hand
of the customer or between harder items in the grocery bag.

External bruising mainly occurs before the fruit is packed, which allows the removal of most of
the damaged fruit at origin. Internal bruising, however, occurs mainly during or after packing.
The riper the fruit, the more readily it bruises. Degree of bruising under given conditions is not
related to size, weight or mass of fruit in any one cultivar, however, although the latter do differ
in their susceptibility to bruising.

Mechanical injury can be prevented, or at least reduced, only by careful analysis of each step
during handling and by devising ways to minimize throwing, dropping or squeezing the fruit.
Where drops are unavoidable, padding with 1-inch thick foam rubber substantially reduces
injury. Avoid drops of 6 inches or more, whether the fruits hit a solid object or each other.
Dumping fruit into water instead of directly onto a belt can help reduce bruising.

Scuffing and scarring can be minimized by keeping boxes, bins and belts clean and by packing
fruit firmly but not too tightly. A loose pack allows fruits to rotate and rub against each other in
transit, which leads to scuffing injury.

Dump Tank Management

Recent attention by regulators, buyers and the industry has focused on the issue of infiltration of
potential food-borne pathogens, such as Salmonella, through the stem scar or harvest wounds on
fresh-market tomatoes or other fruits and vegetables during submersion in water dump or
flotation tanks and flumes. This concern has been prompted primarily by two outbreaks of
Salmonella in 1990 and 1993 linked to the consumption of fresh tomatoes from a single South
Carolina packinghouse. More recently, Salmonella was identified as the pathogenic agent
responsible for large multi-state food-borne disease outbreaks at retail and food service outlets in
2002 and 2004, respectively.

Figure 40. Infiltration of pathogens into a tomato.

The same strategy for prevention of infiltration of plant pathogens leading to postharvest disease
and decay can be employed to inhibit the internalization of food-borne disease pathogens.
Research has shown that dump tank and/or flume water should be heated above the fruit pulp
temperature to prevent air spaces of the fruit tissue from contracting. This constriction causes a
vacuum, which draws pathogenic microorganisms in the water through the stem scar and into the
internal seed cavity, where they are protected from the action of sanitizers (Figure 40).

Investigations at packing houses have led to the recommendation that postharvest immersion
water should be maintained at temperatures of 10 degrees F (6.6 degrees C) above the highest
tomato pulp to prevent water and microorganism uptake. Personnel involved with the dumping
operation should not guess at the temperatures; use a calibrated thermometer to check both the
fruit pulp temperature and water temperature. Although commercial practices vary, a common
set point to maintain for water temperature is 104 degrees F (40 degrees C). Also, avoid the
necessity and cost of having to heat water by providing shade to incoming bins of tomatoes in the
pre-grade staging area.

Figure 41. Partial submersion of tomatoes in a dump tank.

Pathogen infiltration can also occur by the pressure of tomatoes being submerged too deeply for
too long in wash tanks or flumes (Figure 41). As a general recommendation, tomatoes should not
be submerged in wash water more than 12 inches per layer of fruit for longer than 1 minute.

Although chlorination of dump tank and flume waters does not disinfect contaminated tomatoes
or those that have infiltrated pathogens through the stem scar, it does help to keep the water
sanitized by reducing the number of organisms capable of inoculating healthy fruit.

In dump tank water, chlorine exists in both the available and unavailable forms. Only free
(available) chlorine is effective as a water sanitizer. However, the amount of free chlorine in the
water decreases as volume of leaves, stems, soil, and other organic matter increase in the dump
tank. Water pH also must be controlled — ideally between 6.0 and 7.5 in pH — to help keep the
free chlorine (hypochlorous acid) in its available form. Research has demonstrated that the free
chlorine concentration should be held between 100 and 150 ppm in tomato dump tank and wash
waters.

A number of chlorine test kits on the market can be used to measure free (available) chlorine, but
none can differentiate between hypochlorous acid and hypochlorite ions, both considered in the
available form, in the water. Test kits measure both of these forms of chlorine as a concentration
of available form. Only the hypochlorous acid, however, is actively sanitizing the water.

So what you really want to measure is only the available and active form of chlorine
(hypochlorous acid) sanitizing the water, not the total concentration of chlorine (hypochlorous
acid + hypochlorite ions) that is present in the water. A newly developed method to perform this
task currently is in use in tomato packing operations. It is called the Oxidation Reduction
Potential (ORP) system.

How does it work? First, a given dose of chlorine is added to water, some of which produces
hypochlorous acid (HOCl). This substance is what is called a strong oxidizing agent. What does
it do? It causes a chemical reaction called oxidation to occur. Oxidation is defined as the transfer
of electrons from one substance to another. So HOCl oxidizes human pathogen microbes present
in the water, causing them to lose electrons from their membranes. This in turn interrupts their
metabolic functions, causing their death. Since there is a physical transfer of electrons between
substances, a very weak voltage arises, called the electrical potential, and this can be quantified
with a voltmeter.

The ORP produced by the oxidizing action of HOCl is measured in millivolts (mV) which are
displayed using an ORP meter as shown in Figure 42. The stronger the ORP signal
(hypochlorous acid activity), the higher is the number displayed on the meter and the faster the
death rate of pathogens. Based on research at the University of California-Davis, the lowest
target ORP value to achieve pathogen kill is a minimum of 650 mV. Most importantly, since
ORP measures sanitizer activity versus concentration, this value gives you a more accurate, direct
measure of how well the human pathogens in your wash water are being killed.

Sanitation

Maintaining good sanitation throughout harvesting and handling tomatoes is extremely
important. Human pathogens (those causing food-borne illness) can be transmitted by direct
contact from infected employees or animals, or through contaminated equipment and water. Once
a tomato is infected, pathogens are difficult or impossible to remove without some form of heat
treatment (i.e., cooking, pasteurization). Of course, fresh tomatoes are normally consumed raw.
Employees are the number one source of human pathogens, so training field and packing house
workers in proper hygiene techniques is critical.

Portable toilets equipped with hand-wash stations must be available, well stocked and used by all
harvest crew members (Figure 43). Field containers (picking buckets, bins) and harvest aids
(knives, gloves) must be cleaned and sanitized on a daily basis. Likewise, training, monitoring
and enforcement of employee hygiene practices, such as proper hand washing after using the
toilet, among packing shed employees must be documented to reduce the risk of human pathogen
contamination to fresh produce.

For many years packing sheds were not considered food handling businesses and, aside from
sweeping floors to remove waste material and blowing debris off equipment with an air hose,
sanitation was minimal to non-existent. Just one source of human pathogen introduction,
however, at any point, can potentially contaminate all tomatoes passing through the line.

The packing shed sanitation program should include the following:

a Master Sanitation Schedule for cleaning all areas that do not come into contact with
produce (i.e., drains, overhead structures, coolers, etc.) on a regular basis;

written specific standard operating procedures (SOPs) for cleaning and sanitizing all
product contact equipment and monitor to be sure the procedures are followed;

implementation of a pest control and animal exclusion program.

All water used for washing fresh tomatoes in the field (field-packed) or at the packing shed, as
well as water for hydrocooling, should be sanitized. The most commonly used sanitizer is some
form of chlorine. While research has shown that chlorinated water cannot sterilize fresh produce,
the rationale for adding chlorine is to keep the number of human pathogens from concentrating in
the water and cross-contaminating every piece of product that passes through it. Maintaining
consistent and proper levels of chlorine in wash/cooling water is critical.

Chlorination can be accomplished by several methods: using a gas injection system, adding
bleach (sodium hypochlorite), or dissolving calcium hypochlorite tablets. Monitor chlorination
levels in the water frequently during operation with a free-chlorine test kit or ORP meter.

Figure 44. Testing pH regularly will help maintain the maximum disinfectant activity of chlorine in wash or cooling water.

Since pH also has a drastic effect on chlorine’s ability to disinfect, maintain the pH of
wash/cooling water between 6.0 and 7.5 to reduce the amount of chlorine needed to maintain the
recommended available (free) chlorine levels (Figure 44). Excessive use of chlorine, though, can
cause “gassing off” (objectionable chlorine odor), can irritate workers’ skin, is corrosive to
equipment, and increases sanitation costs.

Both chlorine levels and pH measurements must be documented on a quality control form in
order to comply with third party audits.

Grading and Packing

Federal grade standards for field-grown tomatoes include U. S. No. 1, U. S. No. 2, U.S.
Combination and U.S. No. 3. Most buyers will accept only the equivalent of U. S. No. 1 grade or
higher. Tolerances for U. S. No. 1 grade state that tomatoes should have no more than 15 percent
total defects (maturity, color, shape), including 10 percent serious damage (scarring, bruising,
sunburn, discoloration) and 5 percent decay (blossom-end rot) in any lot of tomatoes examined.
Some buyers expect higher quality than these limits.

Georgia tomatoes are graded and packed at the breaker stage of maturity, based on size. Federal
color classification requirements define “breakers” as when there is a definite break in color
from green to tannish-yellow, pink or red on not more than 10 percent of the external
tomato surface.

Figure 45. Commercial tomato sizing rings.

Tomatoes must be graded to achieve uniform shape, color and size. Tomatoes are sized by
passing them over a series of perforated belts with holes corresponding to the maximum
allowable diameter for the particular size (Table 10; Figure 45). Georgia growers typically pack
only 5 x 6, 6 x 6, and 6 x 7 numeric sizes into jumble-packed fiberboard cartons to a net weight
of 25 pounds.

Table 10. USDA size classifications for field harvested tomatoes.

Classification

Minimum Diameter1

Maximum Diameter2

Carton Size/Arrangement3

Small

2-4/32 in. (5.4 cm)

2-9/32 in. (5.79 cm)

7 x 7

Medium

2-8/32 in. (5.72 cm)

2-17/32 in. (6.43 cm)

6 x 7

Large

2-16/32 in. (6.35 cm)

2-25/32 in. (7.06 cm)

6 x 6

Extra Large

2-24/32 in. (7.00 cm)

-----

5 x 6

1Will not pass through a round opening of the designated diameter when tomato is placed with the greatest transverse diameter across the opening.2Will pass through a round opening of the designated diameter in any position.3Designates number of rows of tomatoes in top layer.

In recent years major retailers such as WalMart, Kroger, etc., have requested growers to pack
their produce in reusable plastic containers (RPCs) because containers offer more durability and
versatility, can be properly sanitized, and contain bar codes for easy traceback purposes (Figure
46).

Containers must provide good ventilation, with at least 5 percent of any container side being
open so as not to restrict air movement through the container. Avoid packing in second-hand or
used containers, which are unacceptable to buyers. Shipping containers must not be under- or
over-filled since this will result in short weights and bruise damage to the tomatoes upon
stacking. Use eye appealing, reinforced containers giving the name and address of the packer and
having the size or weight of the product clearly marked on the package.

Cooling and Shipping

Figure 47. Commercial forced air cooling system.

Since the tomato is a tropical fruit, it is adversely affected by exposure to refrigeration
temperatures (less than 50 degrees F) during storage. While several cooling methods can be
used, “forced air” cooling is recommended. Tomato cartons and RPCs are placed in parallel
rows in front of exhaust fans in specially designed refrigerated rooms. A canvas covering is
spread over the top containers, draping to the floor as shown in Figure 47. When the exhaust fans
are turned on, a negative air pressure is produced, which in turn pulls the cold air through the
containers and is then lifted up toward the refrigerated units for recooling. This circular process
allows faster cooling of the product. Once tomatoes are cooled to the appropriate storage
temperature, a solenoid switch turns the fans off and the room becomes a storage cooler. Forced
air cooling is more advantageous than room cooling because field heat is removed more rapidly,
permitting longer shelf-life of the product.

Forced-air coolers are slightly more expensive to build than conventional room coolers because
of the fans and extra refrigeration capacity needed. However, proper utilization of forced-air
coolers significantly enhances quality and shelf life. Once pre-cooled, colored and ripe tomatoes
must be held between 50-55 degrees F and 95 percent relative humidity for a 7-10 day shelf life.
Pre-cooling tomatoes before loading into transit trailers is critical. Truck coolers are not designed to remove field heat from tomatoes. They have only enough refrigeration capacity to
maintain temperature once tomatoes are cooled. Tomatoes loaded in a transit trailer at 90 degrees
F will likely arrive at the market at 90 degrees F. Tomatoes will be soft and overripe and buyers
will not accept them.

Figure 48. Blotchy coloring, surface pitting and black mold decay are evidence that these tomatoes were stored at too low a temperature.

Tomatoes are subject to chilling injury when held at temperatures below 50 degrees F if held
longer than 2 weeks, or at 45 degrees F if held longer than 6-8 days. The consequences of
chilling injury are failure to develop full color and flavor, blotchy, irregular color development,
surface pitting, increased decay (especially black mold caused by Alternaria spp.), and browning
of seeds (internal) (Figure 48).

Tomatoes are also susceptible to water loss through the stem scar. Shriveling becomes evident
with as little as three percent loss in weight if held at less than 85 percent relative humidity.

Tomatoes are moderate to heavy ethylene producers. Ethylene is a natural ripening gas produced
by certain fruits and vegetables that can cause physiological and pathological disorders in
ethylene-sensitive commodities. Shipping “mixed loads” of tomatoes with other sensitive
commodities such as cucumbers, peppers, lettuce, and other leafy greens can cause quality
problems (i.e., loss of chlorophyll, accelerated decay) in these commodities and should be
avoided.

Resources

Ceponis, M.J., and Butterfield, L.E. “Losses in fresh tomatoes at the retail and consumer levels in
greater New York area.” Journal of the American Society for Horticultural Science 104:751-754.
1979.

Marketing

Esendugue Greg Fonsah, Extension Economist

Marketing tomatoes or any horticultural product is more than just selling. Marketing includes
planning, production, harvesting, packaging, transportation, distribution, warehousing and
pricing. To be successful, marketing must be responsive to consumers’ demands. Simplistically,
it must be customer oriented.

To add to the multifaceted problems, marketing skills are required and prior determination or
knowledge of one’s targeted market is a necessary condition. Is it direct marketing, marketing to
retail outlets, specialty food stores or wholesalers? Do you need any promotion? Is any specific
harvest time required? All these and more questions need to be addressed. Do consumers demand
quality, freshness, “reasonable” prices or all of the above?

Tomatoes are an important horticultural crop for Georgia in particular and the United States at
large. According to the Georgia Farm Gate and Georgia Agricultural Statistics Service reports,
respectively, this crop ranked 13th and 18th in the 2003 and 2004 Georgia Agricultural
Commodity Rankings, respectively. Furthermore, Georgia is the 7th largest fresh tomato
producing state nationwide. Georgia tomato production has been rising since 1983, when
reported total planted area was 2,800 acres compared to 6,000 acres in 2004. This reflects a 214
percent increase in planted area. In 1993, 1995, 2000 and 2001, areas planted were equal to or
more than 4,000 acres. From 2002 to 2004, this figure surpassed 5,000 acres. Year 2004 reported
the highest area planted (Figure 49).

Harvested area has also been rising at the same rate as planted area. In 1983, although 2,800
acres were planted, only 2,400 acres were harvested, equivalent to 86 percent. This harvested
amount has increased to 5,800 acres in 2004; that is, about a 242 percent increase compared to
1983. Basically, harvested area is following the same trend as planted area except in 1990, when
the recorded harvested and planted area were the same — 3,500 acres (Figure 49).

The most unpredictable trend is tomato yield. According to Georgia Agricultural Statistics
Service, yields were pretty constant from 1983 to 1987. Thereafter, yield escalated exponentially
from 110 cwt per acre in 1987 to 365 cwt per acre in 1992 (Figure 49).

Although the yield took a nose dive to 280 cwt per acre in 1993, the increasing trend continued
until 1996 when yields stood at 420 cwt per acre, the best ever recorded. Even though an
increasing trend was recorded from 1998 to 2003, the worst yield of 170 cwt per acre was
recorded in 2004. This drastic drop in yield was a result of several hurricanes (Frances, Ivan) and
tropical storms that destroyed most of the vegetable farms in southern Georgia (Fonsah, 2005).

Georgia tomato production has risen from 203,000 cwt in 1983 to over a peak of 1.7 million cwt
in 2001. Other relatively good production years were 1994, 2002 and 2003. The drastic drop in
production in 2004 was a result of several hurricanes (Ivan, Frances, Charley, etc.), and tropical
storms that caused serious damage on most of the Georgia farms. On the other hand, although
there has been a great improvement, average seasonal prices per cwt has been a roller coaster. In
2004, the price of $45 per cwt was the peak due to the extreme shortage in supply caused by
several hurricanes and tropical storms. The relative peak was in 1995 and 2003 when the average
seasonal price per cwt were $31 and $31.50 respectively (Figure 50).

Export Trend

Due to the North American Free Trade Agreement, NAFTA, trade among the United States,
Canada and Mexico has improved significantly. Presently, Canada is our number one trading
partner for fruits and vegetables.

In 2002, tomato export value to Canada was worth $111.7 million, equivalent to 83 percent of
total U.S. tomato export value; $11.6 million was recorded for export to Mexico, equivalent to
8.6 percent. Other countries that purchased a negligible quantity of tomatoes from time to time
from the United States were the United Kingdom, The Netherlands and Japan (Lucier and
Plummer, 2003).

Import Trend

Although the NAFTA agreement has benefitted trade ties between the United States, Canada and
Mexico, Mexico has benefitted more by continually expanding its tomato sales to the United
States by 14 percent from 2001-2002. The United States imported tomatoes from Mexico worth
$490 million, $412 million, $485 million and $552 million in years 1999, 2000, 2001 and 2002,
respectively (Figure 51). It should be noted here that Mexico also has a comparative advantage in
terms of weather, cheap labor and other conditions. Also, most of the tomato suppliers are U.S. companies based in Mexico to take advantage of the cheap labor and favorable weather
conditions (Lucier and Plummer, 2003).

Mexico was our leading tomato supplier, generating about 69 percent of total import value or
$552 million in 2002. Canada ranked second. A negligible quantity supplied came from the
Netherlands (Figure 51).

Pricing

Supply and demand determine the general price level. Seasonal average prices per cwt have been
fluctuating. In 1990, the seasonal average price per cwt was $27.40 whereas in 2002 the price had
jumped to $31.40 per cwt. The peak price was recorded in 1998 at $35.20 per cwt. The U.S.
average retail price for the first quarter of 2003 was highest compared with 2000, 2001 and 2002,
respectively. Thereafter, the downward trend was consistent with previous years but 2003 was
still the best year in terms of average price obtained per pound of tomatoes (Figure 52).

Tomato prices vary greatly within a season and among years. Most of the price variation within
season is caused by weather effects on production. Price variations among years are caused by
changes in acreage and weather. Little of the price variation is caused by demand changes.
Demand changes are slight from year to year. For recent prices, see University of Georgia
Extension Agricultural Economics website.

Although the dollar per cwt price was the lowest in January 2000, a significant increase
compared to 2001 and 2002 was seen in the fall crop. In December 2002, the best price of about
$50 per cwt was recorded. Overall, there were variations from month to month and from year to
year. This variation has to do with the quantity produced and imported (Figure 53).

Consumers determine the demand by deciding what and how much they will buy, so marketing
efforts must be consumer oriented. Consumers normally reflect their wants in the product and
product characteristics they buy. Characteristics of tomato quality include shape, thickness,
firmness and uniform glossy color. Variety and age determine color. Large tomatoes normally
bring premium prices, regardless of color. The competing states’ production levels determine the
supply.

Wholesalers’ and Distributors’ Purchase Decision for Fresh Produce

A 2002 University of Georgia marketing survey asked wholesalers and distributors to rank their
purchase decision for fresh produce.

The result is summarized in Table 11. It is not surprising that quality is the most important factor
in the wholesalers’ and distributors’ purchasing decision. It was interesting, however, that quality
and price were ranked higher than reliability. Unfortunately, the origin of fresh produce was
ranked last.

Wholesalers/distributors consider quality, price and reliability to be the most important factors in
making a purchase. Being grown in Georgia will not help Georgia growers if their produce
cannot compete on quality, price and reliability. These three factors are the minimal requirements
needed to enter this market and can be thought of as a baseline from which products grown in
Georgia must be differentiated.

Georgia’s reputation for providing quality tomatoes in the quantity demanded has improved.
Competition from other areas in the southeast requires that this reputation be maintained and
improved. As production continues to expand, some growers will not be able to compete.
Production skills alone will not ensure survival. Marketing will increase in importance.

Conclusion

Marketing tomatoes, or any product, is more than selling. Marketing includes production,
distribution, and pricing. To be successful, marketing must be responsive to consumers’
demands. Consumers demand quality, freshness and “reasonable” prices. The U.S. production of
fresh tomatoes has been continually on the rise since 1978 when 156.1 million pounds were
produced. By year 2002, production had increased more than three times to 534.9 million
pounds.

Due to NAFTA, trade among the United States, Canada and Mexico has improved significantly.
Presently, Canada is our number one trading partner for fruits and vegetables. The United States
imported tomatoes from Mexico worth $490 million, $412 million, $485 million and $552
million in years 1999, 2000, 2001 and 2002, respectively.

Supply and demand determine the general price level. Seasonal average prices per cwt have been
fluctuating. In 1990, the seasonal average price per cwt was $27.40 whereas in 2002 the price had
jumped to $31.40 per cwt. Tomato prices vary greatly within a season and among years. Most of
the price variation within a season is caused by weather effects on production. Price variations
among years are caused by changes in acreage and weather. Consumers determine the demand by
deciding what and how much they will buy. Thus, marketing efforts must be consumer oriented.
Consumers normally reflect their wants in the product and product characteristics they buy.

References

Boatright, S.R., and C. McKissick. 2003 Georgia Farm Gate Value Report, AR 04-01, The
University of Georgia College of Agricultural and Environmental Sciences, Center for
Agribusiness and Economic Development.

Boatright, S.R., and C. McKissick . 2004 Georgia Farm Gate Value Report, AR 05-01, The
University of Georgia College of Agricultural and Environ-mental Sciences, Center for
Agribusiness and Economic Development.

Production Costs

Esendugue Greg Fonsah, Extension Economist

Tomato growers can use enterprise budgets to estimate production and break-even costs. Budgets
include cost estimates for those inputs necessary to achieve the specified yields over a period of
years. Since production practices vary among growers, each grower needs to adapt budget
estimates to reflect his or her individual situation.

Types of Costs

Total costs of producing any crop include both variable and fixed costs. The variable or operating
costs vary with the adopted cultural practices. Common variable cost components include seed,
fertilizer, chemicals, fuel, and labor.

Variable costs are further broken down into pre-harvest (Table 12) and harvesting and marketing
operations (Table 13) in the hypothetical budget. This provides you an opportunity to analyze the
costs at different stages of the production process.

*Fertilizer amount and application rates should be based on soil test recommendations.1Metalized plastic for fall planting costs $210 per roll or $378 for 1.8 rolls per acre.2Fall planting includes injectable insecticides and fertigation.

Fixed costs include items such as equipment ownership (depreciation, interest, insurance, and
taxes), management, and general overhead costs (Table 14). Most of these costs are incurred
even if little production takes place and these costs should be considered when planning
production costs.

Table 14. Hypothetical fixed costs of producing fresh tomatoes.

Item

Unit

Quantity

Price

Total

Annual Dept. Payment

Machinery

Acre

1.00

84.90

84.90

Irrigation3

Acre

1.00

67.89

67.89

Land

Acre

1.00

0.00

0.00

Overhead and
Management

$

3,811.24

0.15

571.69

Total Fixed Outlays

724.47

3See irrigation budget on the University of Georgia Department of
Agricultural and Applied Extension Economics Website: http://www.caes.uga.edu/departments/agecon/extension/budgets/non-beef/Vegetables.html.

Total Budgeted Cost per Acre = 11,535.71
(Sum of Tables 12, 13 & 14)

Land cost may either be a variable or a fixed cost. Because it varies significantly from county to
county, from region to region, and whether it is irrigated or non-irrigated, it is not included in this
hypothetical budget. Even if you own the land, there is a cost. Land is a fixed cost in this budget
even though no cost has been recorded. A fixed cost per hour of use shows ownership costs for
tractors and equipment (depreciation, interest, taxes, insurance and shelter). Overhead and
management are 15 percent of all pre-harvest variable expenses. This amount pays for
management and farm costs that cannot be allocated to any one specific enterprise. Overhead
items include utilities, pick-up trucks, farm shop and equipment, and fees.

Cost/Unit of Production

The cost categories are broken down in cost per unit (Table 15). The pre-harvest variable costs
and the fixed costs decline with increasing yields.

Table 15. Hypothetical costs per carton of producing tomatoes.

Costs per Carton

Pre-harvest variable cost per carton

1.96

Harvest and marketing cost per carton

3.60

Fixed outlays per carton

0.37

Total budgeted cost per carton

5.94

Budget Uses

In addition to estimating the total costs and break-even costs for producing tomatoes, there are
other uses of the budget. Estimates of the cash costs (out-of-pocket expenses) provide
information on how much money needs to be borrowed. The cash cost estimates are helpful in
preparing cash flow statements. In the instance of share leases, the cost estimates by item can be
used to more accurately determine a fair share arrangement by the landlord and tenant.

Risk Rated Net Returns

Since yields and prices vary from year to year, an attempt is made to estimate the riskiness of
producing tomatoes. The Extension Agricultural Economics Department uses five different
yields and prices to calculate risk (Table 16). The median values are those prices and yields a
particular tomato grower would anticipate to exceed half the time.

Table 16. Risk rated return for tomatoes yield and prices

Best

Opt

Median

Pess

Worst

Yield (cartons)

2400

2200

2000

1600

1400

Price per
carton

10.00

8.00

6.50

5.00

4.00

Half the time, the grower would anticipate not reaching below these prices and yields.
Optimistic values are those prices and yields tomato growers would expect to reach or exceed
one-year-in-six. The pessimistic values are poor prices and yields that would be expected
one-year-in-six. The best and worst values are those extreme levels that would occur once a
lifetime (1 in 49).

The risk rated section (Table 17) shows a 62 percent chance of covering all costs. About 50
percent of the time, the budgeted grower would expect to net $956 or more. Two-thirds of the
time, he/she would expect to net less than $1,464. One year out of six he would expect to make
more than $1,464 per acre or to lose more than $3,430.

Table 17. Tomato production risk rated returns over total costs net return levels (top row); the chances of obtaining this level or more (middle row); the chances of obtaining this level or less (bottom row).

Best

Optimistic

<---

Expected

--->

Pessimistic

Worst

Returns
($)

5,645

4,082

2,519

956

-506

-1,968

-3,430

Chances

7%

16%

30%

49%

49%

49%

49%

Chances

51%

32%

16%

6%

Chances for Profit: 62%

Base Budgeted Net Revenue: 1,464

Summary

Successful tomato production and management is always challenging and like any agricultural
commodity, it is difficult. However, it remains an economically feasible production enterprise for
many Georgia vegetable growers. Enterprise budgets can be used to aid producers in production
and marketing decisions. For additional or more detailed information, please contact your local
Cooperative Extension office.

Status and Revision History
Published on Sep 07, 2006Published on Sep 08, 2006In Review on Jan 05, 2010Published on Feb 05, 2010Published with Full Review on Jan 04, 2014Published with Full Review on Jan 30, 2017

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